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 A273874 #27 May 07 2021 09:34:33
%S A273874 5,1,2,0,2,0,0,0,0,2,5,1,12,0,3,0,3,0,0,0,0,0,53,1,1,1,2,0,4,0,0,0,5,
%T A273874 2,0,0,2,0,3,0,5,0,0,5,0,0,73,1,3,1,2,0,2,0,5,0,0,2,97,1,4,0,0,0,2,5,
%U A273874 0,0,30,0,0,0,1,1,4,0,0,0,0,0,0,2,26,0,6
%N A273874 Least positive integer k such that k^2 + (k+1)^2 + ... + (k+n-2)^2 + (k+n-1)^2 is the sum of two nonzero squares. a(n) = 0 if no solution exists.
%C A273874 Least positive integer k such that Sum_{i=0..n-1} (k+i)^2 = n*(6*k^2 + 6*k*n - 6*k + 2*n^2 - 3*n + 1)/6 is the sum of two nonzero squares. a(n) = 0 if no k exists for corresponding n.
%e A273874 a(1) = 5 because 5^2 = 3^2 + 4^2.
%e A273874 a(3) = 2 because 2^2 + 3^2 + 4^2 = 2^2 + 5^2.
%Y A273874 Cf. A000404, A034705.
%K A273874 nonn
%O A273874 1,1
%A A273874 _Altug Alkan_, Jun 02 2016
%E A273874 a(7)-a(50) from _Giovanni Resta_, Jun 02 2016
%E A273874 More terms from _Jinyuan Wang_, May 02 2021