A062253 2nd level triangle related to Eulerian numbers and binomial transforms (triangle of Eulerian numbers is first level and triangle with Z(0,0)=1 and Z(n,k)=0 otherwise is 0th level).

1, 3, 0, 7, 4, 0, 15, 30, 5, 0, 31, 146, 91, 6, 0, 63, 588, 868, 238, 7, 0, 127, 2136, 6126, 4096, 575, 8, 0, 255, 7290, 36375, 47400, 16929, 1326, 9, 0, 511, 23902, 193533, 434494, 306793, 64362, 2971, 10, 0, 1023, 76296, 956054, 3421902, 4169418, 1765940, 231462, 6534, 11, 0

Offset: 0

Author

Henry Bottomley, Jun 14 2001

Keywords

• nonn
• tabl

Comments

Binomial transform of n^2*k^n is ((kn)^2 + kn)*(k + 1)^(n - 2); of n^3*k^n is ((kn)^3 + 3(kn)^2 + (1 - k)(kn))*(k + 1)^(n - 3); of n^4*k^n is ((kn)^4 + 6(kn)^3 + (7 - 4k)(kn)^2 + (1 - 4k + k^2)(kn))*(k + 1)^(n - 4); of n^5*k^n is ((kn)^5 + 10(kn)^4 + (25 - 10k)(kn)^3 + (15 - 30k + 5k^2)(kn)^2 + (1 - 11k + 11k^2 - k^3)(kn))*(k + 1)^(n - 5); of n^6*k^n is ((kn)^6 + 15(kn)^5 + (65 - 20k)(kn)^4 + (90 - 120k + 15k^2)(kn)^3 + (31 - 146k + 91k^2 - 6k^3)(kn)^2 + (1 - 26k + 66k^2 - 26k^3 + k^4)(kn))*(k + 1)^(n - 6). This sequence gives the (unsigned) polynomial coefficients of (kn)^2.

Examples

			Rows start:
 (1),
 (3,0),
 (7,4,0),
 (15,30,5,0),
 ...
		

Crossrefs

First column is A000225. Diagonals include A000007, A009056. Row sums are A000254. Taking all the levels together to create a pyramid, one face would be A010054 as a triangle with a parallel face which is Pascal's triangle (A007318) with two columns removed, another face would be a triangle of Stirling numbers of the second kind (A008277) and a third face would be A000007 as a triangle, with a triangle of Eulerian numbers (A008292), A062253, A062254 and A062255 as faces parallel to it. The row sums of this last group would provide a triangle of unsigned Stirling numbers of the first kind (A008275).

Programs

PARI

E(n, k) = if ((n<0) || (k<0), 0, if ((n==0) && (k==0), 1, (k+1)*E(n-1, k)+(n-k)*E(n-1, k-1)));
A2(n, k) = if ((n<0) || (k<0), 0, (k+2)*A2(n-1, k)+(n-k)*A2(n-1, k-1)+E(n, k));
row2(n) = vector(n+1, k, A2(n,k-1)); \\ Michel Marcus, Jan 27 2025

Formula

A(n, k) = (k+2)*A(n-1, k)+(n-k)*A(n-1, k-1)+E(n, k) where E(n, k)=(k+1)*E(n-1, k)+(n-k)*E(n-1, k-1) and E(0, 0)=1 is a triangle of Eulerian numbers, essentially A008292.

Extensions

More terms from Michel Marcus, Jan 27 2025