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 A176663 #29 Feb 08 2025 23:35:31 %S A176663 1,1,1,1,0,1,1,2,-2,1,1,-4,9,-5,1,1,20,-41,30,-9,1,1,-100,233,-195,76, %T A176663 -14,1,1,620,-1531,1429,-659,161,-20,1,1,-4420,11537,-11703,6110, %U A176663 -1799,302,-27,1,1,35900,-98047,106421,-61174,20650,-4234,519,-35,1 %N A176663 T(n, k) = [x^k] Sum_{j=0..n} j!*binomial(x, j), for 0 <= k <= n, triangle read by rows. %F A176663 From _Peter Luschny_, Jul 02 2019: (Start) %F A176663 Sum_{k=0..n} T(n, k)*x^k = Sum_{k=0..n} (x)_k, where (x)_k denotes the falling factorial. %F A176663 Let T be the lower triangular matrix associated to the T(n, k) and S the lower triangular matrix associated to the Stirling set numbers S2(n, k). Then S*T = A186020 (seen as a matrix) and T*S = A000012 (seen as a matrix). (End) %F A176663 T(n, k) = Sum_{i=0..n-k} Stirling1(i+k, k). - _Igor Victorovich Statsenko_, May 25 2024 %e A176663 Triangle starts: %e A176663 {1}, %e A176663 {1, 1}, %e A176663 {1, 0, 1}, %e A176663 {1, 2, -2, 1}, %e A176663 {1, -4, 9, -5, 1}, %e A176663 {1, 20, -41, 30, -9, 1}, %e A176663 {1, -100, 233, -195, 76, -14, 1}, %e A176663 {1, 620, -1531, 1429, -659, 161, -20, 1}, %e A176663 {1, -4420, 11537, -11703, 6110, -1799, 302, -27, 1}, %e A176663 {1, 35900, -98047, 106421, -61174, 20650, -4234, 519, -35, 1}, %e A176663 {1, -326980, 928529, -1066279, 662506, -248675, 59039, -8931, 835, -44, 1} %p A176663 with(PolynomialTools): %p A176663 T_row := n -> CoefficientList(expand(add(k!*binomial(x, k), k=0..n)), x): %p A176663 ListTools:-Flatten([seq(T_row(n), n=0..9)]); # _Peter Luschny_, Jul 02 2019 %t A176663 p[x_, n_] := Sum[k! Binomial[x, k], {k, 0, n}]; %t A176663 Table[CoefficientList[FunctionExpand[p[x, n]], x], {n, 0, 10}] // Flatten %t A176663 (* Alternative: *) %t A176663 Table[CoefficientList[FunctionExpand[Sum[FactorialPower[x, k], {k, 0, n}]], x], {n, 0, 10}] // Flatten (* _Peter Luschny_, Jul 02 2019 *) %Y A176663 Row sums are A040000. Alternating row sums are A058006, which are also T(n,1). %Y A176663 Cf. A186020. %K A176663 sign,tabl %O A176663 0,8 %A A176663 _Roger L. Bagula_, Apr 23 2010 %E A176663 Edited by _Peter Luschny_, Jul 02 2019