This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A162586 #4 Jul 22 2025 06:55:44 %S A162586 2,3,5,8,9,12,15,18,20,24,27,32,45,54,60,75,78,80,90,102,110,120,128, %T A162586 135,162,165,170,180,192,195,200,234,243,275,288,312,330,333,360,384, %U A162586 408,432,440,450,465,480,495,500,513,540,612,620,624,675,684,702,729 %N A162586 Integers n for which k = (7 * (256^n - 16^n) + n^2) / (n * (8n + 7)) is an integer. %C A162586 8n + 7 is almost always prime. It is first composite for 8 * 372060 + 7 = 2976487 = 863 * 3449. %Y A162586 Cf. A162587 %Y A162586 Cf. A158034, A158035 %Y A162586 Cf. A161896, A161897 %K A162586 easy,nonn %O A162586 1,1 %A A162586 _Reikku Kulon_, Jul 07 2009