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 A226504 #17 Mar 24 2016 16:26:58 %S A226504 1,1,2,4,1,8,4,3,16,12,13,9,2,32,32,42,42,35,12,8,64,80,120,145,159, %T A226504 133,86,52,32,6,128,192,320,440,559,600,591,440,380,248,164,48,30,256, %U A226504 448,816,1240,1745,2154,2503,2529,2358,2112,1828,1314,944,468,258,150,24 %N A226504 Irregular triangle read by rows: T(n,k) = number of set partitions of [1..n] with dimension k. %H A226504 Alois P. Heinz, <a href="/A226504/b226504.txt">Rows n = 0..50, flattened</a> %H A226504 B. Chern, P. Diaconis, D. M. Kane, R. C. Rhoades, <a href="http://arxiv.org/abs/1304.4309">Closed expressions for averages of set partition statistics</a>, <a href="http://math.stanford.edu/~rhoades/FILES/setpartitions.pdf">[PDF]</a>, 2013. Also arXiv:1304.4309 (2013). %e A226504 Triangle begins: %e A226504 1 %e A226504 1 %e A226504 2 %e A226504 4 1 %e A226504 8 4 3 %e A226504 16 12 13 9 2 %e A226504 32 32 42 42 35 12 8 %e A226504 64 80 120 145 159 133 86 52 32 6 %e A226504 128 192 320 440 559 600 591 440 380 248 164 48 30 %e A226504 ... %Y A226504 Cf. A226505. Row sums = A000110. %Y A226504 Columns k=0-1 give: A011782, A001787(n-2) (for n>1). %K A226504 nonn,tabf %O A226504 0,3 %A A226504 _N. J. A. Sloane_, Jun 10 2013 %E A226504 More terms from _Alois P. Heinz_, Mar 24 2016