A128578 Main diagonal of table A128570.

1, 2, 24, 580, 21420, 1068480, 67189248, 5098406400, 453030209280, 46120247659200, 5290918350734016, 675157532791996800, 94836990558591590400, 14538639675855504384000, 2415072877848471727687680

Offset

0,2

Comments

Limit n->infinity (a(n)/n!)^(1/n) = 12.67567... . - Vaclav Kotesovec, Mar 19 2016

Links

Vaclav Kotesovec, Table of n, a(n) for n = 0..350

Prog

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

Crossrefs

Cf. A128570 (triangle), rows: A128318, A128571, A128572, A128573, A128574, A128575, A128576; A128577 (square of row 0), A128579 (antidiagonal sums).

Sequence in context: A014298 A280794 A090316 * A186632 A089835 A210909

Adjacent sequences: A128575 A128576 A128577 * A128579 A128580 A128581

Keyword

nonn

Author

Paul D. Hanna, Mar 11 2007

Status

approved