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A212273 a(n) = n * A000699(n). 1
1, 2, 12, 108, 1240, 16980, 267624, 4750872, 93615408, 2026018980, 47764893000, 1218621868200, 33459133580496, 983950866169544, 30862364045494800, 1028656519404191280, 36312294166359724128, 1353561646509338629572, 53133041579508472510728 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..19.

FORMULA

a(n) = [x^n] A178685(x)^n.

a(n) ~ n^(n+1) * 2^(n+1/2) / exp(n+1). - Vaclav Kotesovec, Feb 22 2014

EXAMPLE

x + 2*x^2 + 12*x^3 + 108*x^4 + 1240*x^5 + 16980*x^6 + 267624*x^7 + 4750872*x^8 + ...

PROG

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

CROSSREFS

Cf. A000699, A178685.

Sequence in context: A301411 A217803 A177409 * A055897 A210997 A052563

Adjacent sequences:  A212270 A212271 A212272 * A212274 A212275 A212276

KEYWORD

nonn

AUTHOR

Michael Somos, May 12 2012

STATUS

approved

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Last modified July 15 22:48 EDT 2019. Contains 325061 sequences. (Running on oeis4.)