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 A287166 #6 Feb 16 2025 08:33:46 %S A287166 7,22,31,37,45,67,55,61,69,70,79,82,94,108,85,93,103,106,111,132,109, %T A287166 126,139,117,147,146,130,145,144,133,153,167,141,154,160,172,159,166, %U A287166 187,157,177,174,175,0,178,165 %N A287166 Smallest number with exactly n representations as a sum of 7 nonzero squares or 0 if no such number exists. %H A287166 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/SquareNumber.html">Square Number</a> %H A287166 <a href="/index/Su#ssq">Index entries for sequences related to sums of squares</a> %F A287166 A025431(a(n)) = n for a(n) > 0. %e A287166 a(1) = 7 because 7 is the smallest number with exactly 1 representation as a sum of 7 nonzero squares: 7 = 1^2 + 1^2 + 1^2 + 1^2 + 1^2 + 1^2 + 1^2; %e A287166 a(2) = 22 because 22 is the smallest number with exactly 2 representations as a sum of 7 nonzero squares: 22 = 1^2 + 1^2 + 1^2 + 1^2 + 1^2 + 1^2 + 4^2 = 1^2 + 1^2 + 2^2 + 2^2 + 2^2 + 2^2 + 2^2, etc. %Y A287166 Cf. A016032, A025414, A025416, A025431, A080654, A287165, A287167. %K A287166 nonn %O A287166 1,1 %A A287166 _Ilya Gutkovskiy_, May 20 2017