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A087912 Expansion of exp(2*x/(1-x))/(1-x). +0
1
1, 3, 14, 86, 648, 5752, 58576, 671568, 8546432, 119401856, 1815177984, 29808908032, 525586164736, 9898343691264, 198227905206272, 4204989697906688, 94163381359509504, 2219240984918720512 (list; graph; listen)
OFFSET

0,2

FORMULA

a(n) = n!*LaguerreL(n, -2). a(n) = Sum_{k=0..n} 2^k*(n-k)!*binomial(n, k)^2.

MAPLE

a := proc(n) option remember: if n=0 then RETURN(1) fi: if n=1 then RETURN(1) fi: (2*n-1)*a(n-1) - (n-2)*(n-2)*a(n-2) end:for n from 1 to 18 do printf(`%d, `, a(n)) od: - Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Sep 26 2006

CROSSREFS

Sequence in context: A005189 A074520 A127715 this_sequence A051818 A091102 A132624

Adjacent sequences: A087909 A087910 A087911 this_sequence A087913 A087914 A087915

KEYWORD

nonn

AUTHOR

Vladeta Jovovic (vladeta(AT)Eunet.yu), Oct 18 2003

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Last modified August 19 23:53 EDT 2008. Contains 142930 sequences.


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