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 A264434 #22 Jan 30 2021 02:12:46 %S A264434 1,0,1,0,-1,1,0,1,-3,1,0,-1,7,-6,1,0,1,-15,25,-10,1,0,0,31,-90,65,-15, %T A264434 1,0,-7,-56,301,-350,140,-21,1,0,33,35,-938,1701,-1050,266,-28,1,0, %U A264434 -102,423,2485,-7686,6951,-2646,462,-36,1,0,240,-3219,-3450,31885 %N A264434 Triangle read by rows, inverse Bell transform of the third-order Bell numbers, T(n,k) for n >= 0 and 0 <= k <= n. %e A264434 [ 1] %e A264434 [ 0, 1] %e A264434 [ 0, -1, 1] %e A264434 [ 0, 1, -3, 1] %e A264434 [ 0, -1, 7, -6, 1] %e A264434 [ 0, 1, -15, 25, -10, 1] %e A264434 [ 0, 0, 31, -90, 65, -15, 1] %e A264434 [ 0, -7, -56, 301, -350, 140, -21, 1] %e A264434 [ 0, 33, 35, -938, 1701, -1050, 266, -28, 1] %e A264434 [ 0, -102, 423, 2485, -7686, 6951, -2646, 462, -36, 1] %o A264434 (Sage) # uses[bell_transform from A264428, inverse_bell_transform from A264429] %o A264434 def A264434_matrix(dim): %o A264434 uno = [1]*dim %o A264434 bell_numbers = [sum(bell_transform(n, uno)) for n in range(dim)] %o A264434 bell_number_2 = [sum(bell_transform(n, bell_numbers)) for n in range(dim)] %o A264434 bell_number_3 = [sum(bell_transform(n, bell_number_2)) for n in range(dim)] %o A264434 return inverse_bell_transform(dim, bell_number_3) %o A264434 A264434_matrix(10) %Y A264434 Cf. A048993, A264428, A264429, A264431. %K A264434 sign,tabl %O A264434 0,9 %A A264434 _Peter Luschny_, Dec 02 2015