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 A265606 #25 Jul 31 2025 07:01:38 %S A265606 1,0,1,0,1,1,0,5,3,1,0,45,23,6,1,0,585,275,65,10,1,0,9945,4435,990, %T A265606 145,15,1,0,208845,89775,19285,2730,280,21,1,0,5221125,2183895,456190, %U A265606 62965,6370,490,28,1,0,151412625,62002395,12676265,1715490,171255,13230,798,36,1 %N A265606 Triangle read by rows: The Bell transform of the quartic factorial numbers (A007696). %H A265606 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. %H A265606 Peter Luschny, <a href="https://oeis.org/wiki/User:Peter_Luschny/BellTransform">The Bell transform</a> %e A265606 [1], %e A265606 [0, 1], %e A265606 [0, 1, 1], %e A265606 [0, 5, 3, 1], %e A265606 [0, 45, 23, 6, 1], %e A265606 [0, 585, 275, 65, 10, 1], %e A265606 [0, 9945, 4435, 990, 145, 15, 1], %e A265606 [0, 208845, 89775, 19285, 2730, 280, 21, 1], %t A265606 (* The function BellMatrix is defined in A264428. *) %t A265606 rows = 10; %t A265606 M = BellMatrix[Pochhammer[1/4, #] 4^# &, rows]; %t A265606 Table[M[[n, k]], {n, 1, rows}, {k, 1, n}] // Flatten (* _Jean-François Alcover_, Jul 23 2019 *) %o A265606 (Sage) # uses[bell_transform from A264428] %o A265606 def A265606_row(n): %o A265606 multifact_4_1 = lambda n: prod(4*k + 1 for k in (0..n-1)) %o A265606 mfact = [multifact_4_1(k) for k in (0..n)] %o A265606 return bell_transform(n, mfact) %o A265606 [A265606_row(n) for n in (0..7)] %Y A265606 Cf. A007696, A264428, A264429. %Y A265606 Bell transforms of other multifactorials are: A000369, A004747, A039683, A051141, A051142, A119274, A132062, A132393, A203412. %K A265606 nonn,tabl %O A265606 0,8 %A A265606 _Peter Luschny_, Dec 30 2015