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 A303828 #18 Oct 19 2019 10:11:20 %S A303828 1,1,1,1,1,2,2,1,1,1,2,2,1,1,1,2,2,1,1,1,2,2,1,1,1,3,3,2,2,2,4,4,2,2, %T A303828 2,3,3,1,1,1,2,2,1,1,1,2,2,1,1,1,3,3,2,2,2,4,4,2,2,2,3,3,1,1,1,2,2,1, %U A303828 1,1,2,2,1,1,1,3,3,2,2,2,4,4,2,2,2,3,3,1,1,1,2,2 %N A303828 Number of ways of writing n as a sum of powers of 5, each power being used at most 6 times. %H A303828 Alois P. Heinz, <a href="/A303828/b303828.txt">Table of n, a(n) for n = 0..15625</a> %F A303828 G.f.: Product_{k>=0} (1-x^(7*5^k))/(1-x^(5^k)). %F A303828 G.f. A(x) satisfies: A(x) = (1 + x + x^2 + x^3 + x^4 + x^5 + x^6) * A(x^5). - _Ilya Gutkovskiy_, Jul 09 2019 %e A303828 a(26) = 3 because 26=25+1=5+5+5+5+5+1=5+5+5+5+1+1+1+1+1+1. %p A303828 b:= proc(n, i) option remember; `if`(n=0, 1, `if`(i<0, 0, %p A303828 add(b(n-j*5^i, i-1), j=0..min(6, n/5^i)))) %p A303828 end: %p A303828 a:= n-> b(n, ilog[5](n)): %p A303828 seq(a(n), n=0..120); # _Alois P. Heinz_, May 01 2018 %t A303828 m = 100; A[_] = 1; %t A303828 Do[A[x_] = Total[x^Range[0, 6]] A[x^5] + O[x]^m // Normal, {m}]; %t A303828 CoefficientList[A[x], x] (* _Jean-François Alcover_, Oct 19 2019 *) %Y A303828 Number of ways of writing n as a sum of powers of b, each power being used at most b+1 times: A117535 (b=3), A303827 (b=4), this sequence (b=5). %Y A303828 Cf. A277873. %K A303828 nonn %O A303828 0,6 %A A303828 _Seiichi Manyama_, May 01 2018