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A182958 G.f.: A(x) = x/Series_Reversion(x*G(x)) where G(x) = Sum_{n>=0} n!^2*x^n. 1
1, 1, 3, 26, 435, 11454, 429982, 21731604, 1422610371, 117184594070, 11870433500970, 1451034234272556, 210686605349115246, 35851934993572153260, 7068013569547157285340, 1598270770810393333641640 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

LINKS

Table of n, a(n) for n=0..15.

FORMULA

G.f. satisfies: A(x) = G(x/A(x)) where A(x*G(x)) = G(x) = Sum_{n>=0} n!^2*x^n.

G.f. satisfies: [x^n] A(x)^(n+1)/(n+1) = n!^2.

EXAMPLE

G.f.: A(x) = 1 + x + 3*x^2 + 26*x^3 + 435*x^4 + 11454*x^5 +...

G.f. satisfies A(x) = G(x/A(x)) where A(x*G(x)) = G(x) begins:

G(x) = 1 + x + 2!^2*x^2 + 3!^2*x^3 + 4!^2*x^4 + 5!^2*x^5 +...

so that:

A(x) = 1 + x/A(x) + 2!^2*x^2/A(x)^2 + 3!^2*x^3/A(x)^3 + 4!^2*x^4/A(x)^4 +...

PROG

(PARI) {a(n)=polcoeff(x/serreverse(sum(m=1, n+1, (m-1)!^2*x^m)+x^2*O(x^n)), n)}

CROSSREFS

Sequence in context: A192554 A206402 A122949 * A174423 A049088 A089041

Adjacent sequences:  A182955 A182956 A182957 * A182959 A182960 A182961

KEYWORD

nonn

AUTHOR

Paul D. Hanna, Dec 31 2010

STATUS

approved

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Last modified April 17 06:40 EDT 2014. Contains 240633 sequences.