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 A265605 #27 Jun 16 2023 16:22:24 %S A265605 1,0,1,0,1,1,0,-1,3,1,0,3,-1,6,1,0,-15,5,5,10,1,0,105,-35,0,25,15,1,0, %T A265605 -945,315,-35,0,70,21,1,0,10395,-3465,490,-35,70,154,28,1,0,-135135, %U A265605 45045,-6895,630,-105,378,294,36,1 %N A265605 Triangle read by rows: The inverse Bell transform of the triple factorial numbers (A007559). %H A265605 Peter Luschny, <a href="https://oeis.org/wiki/User:Peter_Luschny/BellTransform">The Bell transform</a> %H A265605 Richell O. Celeste, Roberto B. Corcino, and Ken Joffaniel M. Gonzales, <a href="https://cs.uwaterloo.ca/journals/JIS/VOL20/Celeste/celeste3.html">Two Approaches to Normal Order Coefficients</a>, Journal of Integer Sequences, Vol. 20 (2017), Article 17.3.5. %e A265605 [ 1] %e A265605 [ 0, 1] %e A265605 [ 0, 1, 1] %e A265605 [ 0, -1, 3, 1] %e A265605 [ 0, 3, -1, 6, 1] %e A265605 [ 0, -15, 5, 5, 10, 1] %e A265605 [ 0, 105, -35, 0, 25, 15, 1] %e A265605 [ 0, -945, 315, -35, 0, 70, 21, 1] %o A265605 (Sage) # uses[bell_transform from A264428] %o A265605 def inverse_bell_matrix(generator, dim): %o A265605 G = [generator(k) for k in srange(dim)] %o A265605 row = lambda n: bell_transform(n, G) %o A265605 M = matrix(ZZ, [row(n)+[0]*(dim-n-1) for n in srange(dim)]).inverse() %o A265605 return matrix(ZZ, dim, lambda n,k: (-1)^(n-k)*M[n,k]) %o A265605 multifact_3_1 = lambda n: prod(3*k + 1 for k in (0..n-1)) %o A265605 print(inverse_bell_matrix(multifact_3_1, 8)) %Y A265605 Cf. A007559, A264428, A264429. %Y A265605 Inverse Bell transforms of other multifactorials are: A048993, A049404, A049410, A075497, A075499, A075498, A119275, A122848, A265604. %K A265605 sign,tabl %O A265605 0,9 %A A265605 _Peter Luschny_, Dec 30 2015