A274573 Column 2 of triangle A274570.

1, 3, 39, 1125, 56505, 4354923, 476265591, 70056231213, 13329387478113, 3184105899176739, 932720103991595919, 328710383679927689157, 137188135970104212440721, 66909975066823379752742835, 37706189062081696231083478647, 24312515006613477431766856702797, 17784145956730483348850500758855969, 14647274671009402833580157237962722147, 13492886769176913829412675003231182928079

Offset

0,2

Comments

Triangle A274570 transforms diagonals in the array A274390 of coefficients of successive iterations of Euler's tree function (A000169).

Links

Paul D. Hanna, Table of n, a(n) for n = 0..38

Prog

(PARI) {T(n, k)=local(F=x,
LW=serreverse(x*exp(-x+x*O(x^(n+2)))), M, N, P, m=max(n, k));
M=matrix(m+3, m+3, r, c, F=x; for(i=1, r+c-2, F=subst(F, x, LW)); polcoeff(F, c));
N=matrix(m+1, m+1, r, c, M[r, c]);
P=matrix(m+1, m+1, r, c, M[r+1, c]);
(n-k)!*(P~*N~^-1)[n+1, k+1]}
/* Print triangle A274570: */
for(n=0, 10, for(k=0, n, print1(T(n, k), ", ")); print(""))
/* Print this sequence, which is column 2 */
for(n=0, 20, print1(T(n+2, 2), ", "))

Crossrefs

Cf. A274570, A274571, A274572, A274574.

Sequence in context: A276964 A367596 A353739 * A278750 A082159 A187536

Adjacent sequences: A274570 A274571 A274572 * A274574 A274575 A274576

Keyword

nonn

Author

Paul D. Hanna, Jun 28 2016

Status

approved