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 A158139 #4 Mar 31 2012 12:35:25 %S A158139 1,4,8,17,23,44,54,85,107,150,178,247,281,366,422,527,591,734,808,975, %T A158139 1079,1272,1388,1633,1761,2036,2204,2513,2695,3068,3266,3677,3923, %U A158139 4374,4638,5167,5449,6022,6362,6983,7343,8054,8436,9199,9647,10464,10936 %N A158139 Number of nondecreasing integer sequences of length 5 with sum zero and sum of absolute values 2n. %C A158139 a(n) = A000041(n)^2 for n<=2 %C A158139 a(n) = A000041(n)^2 - cumulative A000712(2*n-1-length), 0 <= 2*n-1-length <= floor(n/2) [empirical]. %H A158139 R. H. Hardin, <a href="/A158139/b158139.txt">Table of n, a(n) for n=1..999</a> %K A158139 nonn %O A158139 1,2 %A A158139 _R. H. Hardin_ Mar 13 2009