A128574 Row 4 of table A128570.

1, 5, 60, 1020, 21420, 523320, 14399280, 437433780, 14479664640, 517426156800, 19824547680000, 810083131361280, 35155640625638400, 1614680474921256960, 78256021787814850560, 3991780109967777792000, 213813097136418588641280

Offset

0,2

Links

Vaclav Kotesovec, Table of n, a(n) for n = 0..360

Formula

G.f.: A(x) = 1 + 5x*R(x,5)^2, where R(x,5) = 1 + 6*x*R(x,6)^2, R(x,6) = 1 + 7*x*R(x,7)^2, ..., R(x,n) = 1 + (n+1)*x*R(x,n+1)^2, ... and R(x,n) is the g.f. of row n of table A128570.

a(n) ~ 32*n^4*A128318(n)/243. - Vaclav Kotesovec, Mar 19 2016

Prog

(PARI) {a(n)=local(A=1+(n+5)*x); for(j=0, n, A=1+(n+5-j)*x*A^2 +x*O(x^n)); polcoeff(A, n)}

Crossrefs

Cf. A128570 (triangle), other rows: A128318, A128571, A128572, A128573, A128575, A128576; A128577 (square of row 0), A128578 (main diagonal), A128579 (antidiagonal sums).

Sequence in context: A277300 A156125 A260776 * A120976 A384524 A062980

Adjacent sequences: A128571 A128572 A128573 * A128575 A128576 A128577

Keyword

nonn

Author

Paul D. Hanna, Mar 11 2007

Status

approved