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 A265604 #25 Jul 31 2025 07:34:04 %S A265604 1,0,1,0,1,1,0,-2,3,1,0,10,-5,6,1,0,-80,30,-5,10,1,0,880,-290,45,5,15, %T A265604 1,0,-12320,3780,-560,35,35,21,1,0,209440,-61460,8820,-735,0,98,28,1, %U A265604 0,-4188800,1192800,-167300,14700,-735,0,210,36,1 %N A265604 Triangle read by rows: The inverse Bell transform of the quartic factorial numbers (A007696). %H A265604 Peter Luschny, <a href="https://oeis.org/wiki/User:Peter_Luschny/BellTransform">The Bell transform</a> %H A265604 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 A265604 [ 1] %e A265604 [ 0, 1] %e A265604 [ 0, 1, 1] %e A265604 [ 0, -2, 3, 1] %e A265604 [ 0, 10, -5, 6, 1] %e A265604 [ 0, -80, 30, -5, 10, 1] %e A265604 [ 0, 880, -290, 45, 5, 15, 1] %o A265604 (Sage) # uses[bell_transform from A264428] %o A265604 def inverse_bell_matrix(generator, dim): %o A265604 G = [generator(k) for k in srange(dim)] %o A265604 row = lambda n: bell_transform(n, G) %o A265604 M = matrix(ZZ, [row(n)+[0]*(dim-n-1) for n in srange(dim)]).inverse() %o A265604 return matrix(ZZ, dim, lambda n,k: (-1)^(n-k)*M[n,k]) %o A265604 multifact_4_1 = lambda n: prod(4*k + 1 for k in (0..n-1)) %o A265604 print(inverse_bell_matrix(multifact_4_1, 8)) %Y A265604 Cf. A007696, A264428, A264429. %Y A265604 Inverse Bell transforms of other multifactorials are: A048993, A049404, A049410, A075497, A075499, A075498, A119275, A122848, A265605. %K A265604 sign,tabl %O A265604 0,8 %A A265604 _Peter Luschny_, Dec 30 2015