CINXE.COM

<!DOCTYPE html><html lang="en-US"><head><title>Just a moment...</title><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"><meta http-equiv="X-UA-Compatible" content="IE=Edge"><meta name="robots" content="noindex,nofollow"><meta name="viewport" content="width=device-width,initial-scale=1"><style>*{box-sizing:border-box;margin:0;padding:0}html{line-height:1.15;-webkit-text-size-adjust:100%;color:#313131;font-family:system-ui,-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,Helvetica Neue,Arial,Noto Sans,sans-serif,Apple Color Emoji,Segoe UI Emoji,Segoe UI Symbol,Noto Color Emoji}body{display:flex;flex-direction:column;height:100vh;min-height:100vh}.main-content{margin:8rem auto;max-width:60rem;padding-left:1.5rem}@media (width <= 720px){.main-content{margin-top:4rem}}.h2{font-size:1.5rem;font-weight:500;line-height:2.25rem}@media (width <= 720px){.h2{font-size:1.25rem;line-height:1.5rem}}#challenge-error-text{background-image:url(data:image/svg+xml;base64,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);background-repeat:no-repeat;background-size:contain;padding-left:34px}@media (prefers-color-scheme:dark){body{background-color:#222;color:#d9d9d9}}</style><meta http-equiv="refresh" content="390"></head><body class="no-js"><div class="main-wrapper" role="main"><div class="main-content"><noscript><div class="h2"><span id="challenge-error-text">Enable JavaScript and cookies to continue</span></div></noscript></div></div><script>(function(){window._cf_chl_opt={cvId: '3',cZone: "oeis.org",cType: 'managed',cRay: '92cd3d563cd88325',cH: 'mquf71Jgwg2wUbuAenusSzFS9vmJaeMZHcYa.QiOc.A-1744067858-1.2.1.1-3GD2nRQvR4dtltdxKDNI8axnIYj54EvbC4cz5NlYqhOVrDvr2a4JtlmneOCKIVty',cUPMDTk: "\/A005717?__cf_chl_tk=9kKUkR.I1QGgCSdMpI14wEDA6yN8m0r6qcc0tyxfgxE-1744067858-1.0.1.1-xjNi8MO41Gequh_WpDeB6ErYOkTnrKD9O_.0n7LWEgY",cFPWv: 'g',cITimeS: '1744067858',cTTimeMs: '1000',cMTimeMs: '390000',cTplC: 0,cTplV: 5,cTplB: 'cf',cK: "",fa: "\/A005717?__cf_chl_f_tk=9kKUkR.I1QGgCSdMpI14wEDA6yN8m0r6qcc0tyxfgxE-1744067858-1.0.1.1-xjNi8MO41Gequh_WpDeB6ErYOkTnrKD9O_.0n7LWEgY",md: "PoO70iiLfOZG1de3rjyu4iplz4cylm0HoWRA1La4tAg-1744067858-1.2.1.1-Ol.3XhZnF4rRd6M1.bL99tskP7t7l5nU6GfTwvBLmuKDBgYEpW7UxizCKnRs5o3xBRMw4urEcy.bQuSaJf1JGltfU2K1eb4ZVY0kxk0IoY9yAp9_y7nq_ViO0WasDibJTAovLPEmuy0wWoJ_5CZ7ncpcmDgLTo4yZcI2q.73UGhMYHrZduJs_GB50mhbGi3j19lDsdq7qBEqNbwTFUu9l.osUkjt2nOx1y1yW8UOZkcDd0uLnBJvTT6eE3aSIGkKHAxuErDloAs3xyHhikk4dRlDt7ncO1OzgGY70UF8Kcx.Y.5Hd1zob.1iEg2M5IL8i1RPWe2zZkIsrzQKTWPfos6xW1maS1fi3.WfopQsOxUyIF1bh___TPfhZ10CUiJGo5v2ZzVTeJjSqjlAonf95bxfAADKsrL1sFxNz19ikOLb_4wXuIwpB_QQqzACVonjZBnoYS92SEapZ3YW_guCgR84Xm0T2IPeBcNqhcGJ_7xhuA4C.hd1yxRnbR4a17ne72xTQkh2krUXOuncwHv6qEvHVeobZnisJnbe4KpexXFLYjB55F.2drBkvBFnzVNnrmE1h.SDN86spBNF5bCqeC7nkgJNAvUrFbq3faLgP1Y9Z6ShQnvUpjGFsOHnw7Az3K3V7nAD6.9zWAqLJESmeE4B5_f1Jv4v0jryAHKZaSJ99EHQJADKETp8EhpNQg7wWER8f9gMP70uw7b9BQ5MGECXvYOGjDm8zVr8IxvCJLulGD_PD9ppKq5V1VJyhotUonsxyxQ3ujM_E9K.aKgzXPYRNdrmvQVvxcz1vUH1OpxOrZ2jD51NgX5VDRkE_Xur8oOX_XkLGQBXJ91dy7eJYs9sg8JR5xjV1pVQwQoRVSUWjN.DibMQRy4uXFzYV0TYZXQuGsp9WfjMS_6IdMBWxIizEgqejHOyqoQbo.NQBUDAQeLJGyYd1LBHqEOQZSxJptufBvzGfu70E._AyP0KtZyzAdcnz01bG2gVxtlatmW7LPZX3hK.CUdfW5h8TcnlZqx3gvJoNFOpTj57oLbcIAmHb0x3QJW8t93TedmyJH.hxZNlajwlQH_YdDWxmBve",mdrd: "IDoM.G0i1GPQVDsv3q8xS7KixldSKoCvc6Y.w6_bpV8-1744067858-1.2.1.1-2cNkSmdT7iCjDVN0HfAuH7Ec5d3kIZWiNIQDpiRKnsbmQNEHCEioGhk2Z3doxcAZ.BiR.4QXA9LiEKfNIzgRKWVh45iH08YBrSpNxdEQHAkBxZIzt936CmB0XT9L4OYanSdItWd9LlnCLnO.5AIgLHxLkJXT1uQeAgC71pYoYpguVMn8Oqsg8mrEMLM3OhIRdu8LkkSIMrJnVa2gnzdbBmELCbtPY4rPlQrACV_GjEd1V27Iow6wcHDpmPRNLPoUTtZIkMZXc1zNJmyUoIBg2nkfoeY1OCTsB3HczH0xYhSDHAxhfmgOlYSKO5Rghu8UhAQqNfd3F8Rif.5LZd.52xc3K4dEWt2y5BxIOAGUxbX2KBtWMbCDz1G5ZSCdrUJUc5e8xPfrQZ.XT.cksLHXZBYBEagmD4m7OgtjWlR98Z7of6C4vdyl89JvSE_igtSj_d8nd5dzmUA4fJej2iv4HGnh7Ymegsof3_LH8WgfPq13corUaV0CtkqwhiZu_NrGBJ.pr6GgcpbJh46MqBQeyhGS4AyJnscfDhUplbagyezaG3fKmu68Km191IwiJTX5c13pHWdYJ8HL8YcmTlKjYPkiFsaaAc9dTUHgJXWzSUGbT8fDhdwPTf5U_W1rblpnghWKyN4YwH1G4Lwp6CA62ohqX_ZGSRrZj4zItY.hcvxFV00.xtkouSTM8d1bNx5un4lGSyWngow_93.zMBunCanC8zhpMu0gWgnRB.q2SERZV8gAHHHYjrrSkrLAywzp3oRFATDe8GQdJH1eHgH88O1e4ABlTl4ApYFQHZh_ycSBKsX2gaFXzG3UXnsXxyxgL4p1tW5ppPQ8.PMdMGChLRFQAjnE7ByjhRUtqwehSHxNjSNoN5VOikxlbzs7ZYMB3q_kiM3NLUxarnWKpyfqLmBoc9h5R2NyAA1UbxaRLeV9f8uWhQfO7NSXuEmF4MyhgGzl5R_Q52I458fLiMzjG2tWsLEYBsjFFUgqILujytcJVIsa8FJf6M1lrl8R78EL25FAZKaiFhkETWJ.YFMg4fdOcLAEwozL.v2sgo2xt7V55LoT9rLn8RSXXJqmP1Yn8QowI3PEol.60XkNfDkRiUeEmABr2CwX6_LuH2nLHipKUGg_GN9dVu5k7OJ8kegLhJmiNLBEt4bak9Rgr6mGG.d9vO.2KvHF7MhiUV20Qz7mImz2RSCYL.4jMhVPPECl5UUXFgMJkNSRXhJaw54dkeAKSAezlTlBEyqCslMTo_QmvWxz8SaYx9azd5cE5HF9MaxLJtBAZ6VteZ7snvOb4J28vxA.8sf6PF3UI9RnUXjglUHlYT8myq5iH0ngtJXLn9ZcjdhRihgk49SDU7B.nI6sP.EOSbrhdZNHujdtZKyDa4Z1SAKcFgU_A.uuPFEJugxKRrxuZiGfQtrgWau9sG6YvPQ5attZIhLLrdobqH4cOR01DqU7S4qXGnWmJB_tpm09NE7opirxdEFMpmrMxMpIsS9vOm3eR3pxWSm5mBYG05UYvWK_HB1xEW3tPLRKiIiOjqygGqFovraRqLyN5rZKPkRlDmX0jqxTL.BWyc5LO8xXq3Ogtz42gljk4LjZXy1Ruw1mp.SgrCRlGZ9BcmWIkKSFQPnSWBbpJ8V2G6rOn_WXQKyOe8zVB6Fh6nKHs.C93Y2ddXmCHhWJ0WD6UObKVyBiAm0C9ghdCCoKbMU3kq83XY33kTrFVaV70MQDeUAyp1JyA2GgXQP5GlpBwVusxtC4bI_2wDQGmzs7bj0LdxMW_w7RNY3jbcZqEw8hEqN3U5YvtpoVMyAu._G350yMgnT5EcBIT8iURjL7SmBtkTdVpLmImEkdeBizTszbwldMJFRAYAKlUj4Ba3a4LJBoC4ZuN4uurf4r6misALHtaEYKzE0NoxXEYMh8m2sv78u1W4vkBcN4HZOiZ8zXCWPbNXI0eoOYIBzWJ5YB9a4e.SlRtyYY5NUKku7rSk9ee3GpgNWHQS2tqUc4j7Zi5y7kTVTHGm8ahrrkEYgqarI"};var cpo = document.createElement('script');cpo.src = '/cdn-cgi/challenge-platform/h/g/orchestrate/chl_page/v1?ray=92cd3d563cd88325';window._cf_chl_opt.cOgUHash = location.hash === '' && location.href.indexOf('#') !== -1 ? '#' : location.hash;window._cf_chl_opt.cOgUQuery = location.search === '' && location.href.slice(0, location.href.length - window._cf_chl_opt.cOgUHash.length).indexOf('?') !== -1 ? '?' : location.search;if (window.history && window.history.replaceState) {var ogU = location.pathname + window._cf_chl_opt.cOgUQuery + window._cf_chl_opt.cOgUHash;history.replaceState(null, null, "\/A005717?__cf_chl_rt_tk=9kKUkR.I1QGgCSdMpI14wEDA6yN8m0r6qcc0tyxfgxE-1744067858-1.0.1.1-xjNi8MO41Gequh_WpDeB6ErYOkTnrKD9O_.0n7LWEgY" + window._cf_chl_opt.cOgUHash);cpo.onload = function() {history.replaceState(null, null, ogU);}}document.getElementsByTagName('head')[0].appendChild(cpo);}());</script></body></html>