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 A025056 #8 Aug 05 2019 02:06:15 %S A025056 1,7,20,39,64,95,133,177,227,284,346,415,489,570,657,750,849,954,1065, %T A025056 1182,1305,1434,1569,1710,1857,2010,2169,2334,2505,2682,2865,3054, %U A025056 3249,3450,3657,3870,4089,4314,4545,4782,5025,5274,5529,5790,6057,6330,6609,6894 %N A025056 a(n) = position of 3*n^2 in sequence A025051 (numbers of form j*k + k*i + i*j, without repetitions, where 1 <= i <= j <= k). %Y A025056 Cf. A025051. %K A025056 nonn %O A025056 1,2 %A A025056 _Clark Kimberling_ %E A025056 a(5) onward corrected and more terms from _Sean A. Irvine_, Aug 05 2019