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 A281965 #8 Feb 03 2017 18:45:12
%S A281965 1,1,1,2,2,2,3,4,3,3,5,4,4,5,7,5,5,9,6,6,8,9,7,7,13,8,8,12,11,9,10,15,
%T A281965 10,10,16,13,11,14,17,12,12,20,14,13,18,19,14,15,24,15,15,22,20,16,19,
%U A281965 26,17,17,27,20,18,23,27,19,19,33,20,20,28,27,21,23
%N A281965 Number of sets of exactly n positive integers <= n+2 having a square element sum.
%H A281965 Alois P. Heinz, <a href="/A281965/b281965.txt">Table of n, a(n) for n = 0..1000</a>
%F A281965 a(n) = A281871(n+2,n).
%e A281965 a(7) = 4: {1,2,3,6,7,8,9}, {1,2,4,5,7,8,9}, {1,3,4,5,6,8,9}, {2,3,4,5,6,7,9}.
%e A281965 a(8) = 3: {1,2,3,4,5,6,7,8}, {1,3,5,6,7,8,9,10}, {2,3,4,6,7,8,9,10}.
%e A281965 a(9) = 3: {1,2,3,4,5,6,7,10,11}, {1,2,3,4,5,6,8,9,11}, {1,2,3,4,5,7,8,9,10}.
%Y A281965 A diagonal of A281871.
%K A281965 nonn,look
%O A281965 0,4
%A A281965 _Alois P. Heinz_, Feb 03 2017