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 A287165 #6 Feb 16 2025 08:33:46 %S A287165 6,21,30,36,63,54,60,87,78,81,84,111,102,117,108,116,126,129,134,137, %T A287165 132,150,172,165,161,156,177,164,195,191,182,213,180,188,198,0,204, %U A287165 206,215,222,243,212,251,262,233,230 %N A287165 Smallest number with exactly n representations as a sum of 6 nonzero squares or 0 if no such number exists. %H A287165 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/SquareNumber.html">Square Number</a> %H A287165 <a href="/index/Su#ssq">Index entries for sequences related to sums of squares</a> %F A287165 A025430(a(n)) = n for a(n) > 0. %e A287165 a(1) = 6 because 6 is the smallest number with exactly 1 representation as a sum of 6 nonzero squares: 6 = 1^2 + 1^2 + 1^2 + 1^2 + 1^2 + 1^2; %e A287165 a(2) = 21 because 21 is the smallest number with exactly 2 representations as a sum of 6 nonzero squares: 21 = 1^2 + 1^2 + 1^2 + 1^2 + 1^2 + 4^2 = 1^2 + 2^2 + 2^2 + 2^2 + 2^2 + 2^2, etc. %Y A287165 Cf. A016032, A025414, A025416, A025430, A080654, A287166, A287167. %K A287165 nonn %O A287165 1,1 %A A287165 _Ilya Gutkovskiy_, May 20 2017