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 A188229 #7 Jul 22 2025 11:03:39 %S A188229 1,3,7,30,119,527,2395,11376,55368,275735,1397063,7185356,37419881, %T A188229 196993233,1046785509,5608211846,30264466262,164375822152, %U A188229 897938065590,4930713542112,27202861579741,150721902660263,838367664692809 %N A188229 Number of nondecreasing arrangements of n numbers in -n..n with sum zero and not more than two numbers equal. %C A188229 Column 2 of A188236 %H A188229 R. H. Hardin, <a href="/A188229/b188229.txt">Table of n, a(n) for n = 1..31</a> %e A188229 Some solutions for n=4 %e A188229 .-3...-2...-3...-2...-3...-4...-4...-4...-3...-4...-1...-2...-4...-3...-3...-1 %e A188229 .-2...-2...-3....0...-1...-2...-4....0....0...-3....0...-1....0...-3...-1...-1 %e A188229 ..2....0....2....0....2....2....4....0....1....3....0...-1....2....3....0....0 %e A188229 ..3....4....4....2....2....4....4....4....2....4....1....4....2....3....4....2 %K A188229 nonn %O A188229 1,2 %A A188229 _R. H. Hardin_ Mar 24 2011