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 A151338 #4 Jan 30 2017 21:22:19 %S A151338 1,0,1,1,1,1,1,0,0,1,3,7,15,31,56,91,126,126,0,0,0,1,6,25,90,301,938, %T A151338 2737,7455,18711,41811,81081,126126,126126,0,0,0,0,1,10,65,350,1701, %U A151338 7686,32725,132055,505351,1824823,6173167,19339320,55096041 %N A151338 Triangle read by rows: T(n,k) = number of partitions of [1..k] into n nonempty clumps of sizes 1, 2, 3, 4 or 5 (n >= 0, 0 <= k <= 5n). %C A151338 Row n has 5n+1 entries. %H A151338 Moa Apagodu, David Applegate, N. J. A. Sloane, and Doron Zeilberger, <a href="http://arxiv.org/abs/1701.08394">Analysis of the Gift Exchange Problem</a>, arXiv:1701.08394, 2017. %H A151338 David Applegate and N. J. A. Sloane, <a href="http://arxiv.org/abs/0907.0513">The Gift Exchange Problem</a> (arXiv:0907.0513, 2009) %e A151338 The triangle begins: %e A151338 1 %e A151338 0, 1, 1, 1, 1, 1 %e A151338 0, 0, 1, 3, 7, 15, 31, 56, 91, 126, 126 %e A151338 0, 0, 0, 1, 6, 25, 90, 301, 938, 2737, 7455, 18711, 41811, 81081, 126126, 126126 %e A151338 0, 0, 0, 0, 1, 10, 65, 350, 1701, 7686, 32725, 132055, 505351, 1824823, 6173167, 19339320, 55096041, 138654516, 295891596, 488864376, 488864376 %e A151338 0, 0, 0, 0, 0, 1, 15, 140, 1050, 6951, 42315, 241780, 1310925, 6782776, 33549516, 158533375, 713733020, 3046944901, 12246267033, 45892143297, 158167994985, 491492022021, 1336310771796, 3030225834636, 5194672859376, 5194672859376 %e A151338 ... %Y A151338 This is one of a sequence of triangles: A144331, A144385, A144643, A151338, A151359, ... %Y A151338 See A151509, A151510 for other versions. %K A151338 nonn,tabf %O A151338 0,11 %A A151338 _N. J. A. Sloane_, May 13 2009