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 A281966 #8 Feb 03 2017 19:50:43
%S A281966 1,2,2,3,5,6,7,10,13,14,16,21,25,24,31,37,37,40,50,55,51,64,74,69,77,
%T A281966 92,95,89,111,122,110,127,146,145,139,171,181,161,191,213,202,203,243,
%U A281966 250,222,270,292,264,285,328,326,296,362,381,335,383,425,407,388
%N A281966 Number of sets of exactly n positive integers <= n+3 having a square element sum.
%H A281966 Alois P. Heinz, <a href="/A281966/b281966.txt">Table of n, a(n) for n = 0..1000</a>
%F A281966 a(n) = A281871(n+3,n).
%e A281966 a(3) = 3: {1,2,6}, {1,3,5}, {2,3,4}.
%e A281966 a(4) = 5: {1,2,6,7}, {1,3,5,7}, {1,4,5,6}, {2,3,4,7}, {2,3,5,6}.
%e A281966 a(5) = 6: {1,2,3,4,6}, {1,3,6,7,8}, {1,4,5,7,8}, {2,3,5,7,8}, {2,4,5,6,8}, {3,4,5,6,7}.
%Y A281966 A diagonal of A281871.
%K A281966 nonn,look
%O A281966 0,2
%A A281966 _Alois P. Heinz_, Feb 03 2017