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 A271326 #18 Apr 04 2016 12:20:32 %S A271326 3,15,30,51,84,111,150,195,246,318,366,435,510,591,684,771,882,975, %T A271326 1086,1218,1326,1455,1590,1731,1884,2031,2190,2370,2526,2718,2886, %U A271326 3075,3270,3483,3684,3891,4128,4335,4566,4818,5046,5295,5550,5811,6084 %N A271326 a(n) = A269347(3n). %C A271326 This sequence represents the "peaks" of A269347(n), which occur for that sequence when n is divisible by 3. %C A271326 Terms of this sequence are equal to 3n^2 + 3 with predictable frequency; see my comment on A271328. %H A271326 Alec Jones, <a href="/A271326/b271326.txt">Table of n, a(n) for n = 1..10001</a> %Y A271326 Cf. A269347, A271328 %K A271326 nonn,easy %O A271326 1,1 %A A271326 _Alec Jones_, Apr 04 2016