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 A039813 #31 Feb 13 2022 06:31:29 %S A039813 1,5,1,35,15,1,315,215,30,1,3455,3325,725,50,1,44590,56605,17100,1825, %T A039813 75,1,660665,1060780,415555,60900,3850,105,1,11035095,21772595, %U A039813 10606470,1998605,172550,7210,140,1,204904830,486459105,286281665,66528210,7346955,417690,12390,180,1 %N A039813 Matrix 5th power of Stirling2 triangle A008277. %H A039813 Seiichi Manyama, <a href="/A039813/b039813.txt">Rows n = 1..140, flattened</a> %F A039813 E.g.f. k-th column: (( exp(exp(exp(exp(exp(x)-1)-1)-1)-1)-1 )^k)/k!. [corrected by _Seiichi Manyama_, Feb 12 2022] %e A039813 Triangle begins: %e A039813 1; %e A039813 5, 1; %e A039813 35, 15, 1; %e A039813 315, 215, 30, 1; %e A039813 3455, 3325, 725, 50, 1; %e A039813 44590, 56605, 17100, 1825, 75, 1; %e A039813 ... %t A039813 max = 9; m = MatrixPower[Array[StirlingS2, {max, max}], 5]; Table[Take[m[[n]], n], {n, 1, max}] // Flatten (* _Jean-François Alcover_, Mar 03 2014 *) %Y A039813 Cf. A008277, A000357 (first column). %Y A039813 Cf. A039810, A039811, A039812. %K A039813 nonn,tabl %O A039813 1,2 %A A039813 _Christian G. Bower_, Feb 15 1999