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A080833 Expansion of the exponential series Exp[ x/(1 - x - x^2) ]. 0
1, 1, 3, 19, 145, 1401, 16051, 213403, 3223809, 54514225, 1019601091, 20890209891, 465156779473, 11181638663209, 288536019179955, 7953590111627371, 233211718410856321, 7246720953253750113 (list; graph; refs; listen; history; internal format)
OFFSET

0,3

FORMULA

E.G.F. Exp[ x/(1 - x - x^2) ]

a(n)=n!*sum{i=0..n, sum{j=0..n, C(i+j-1, j)C(j, n-i-j)/i!}}; - Paul Barry (pbarry(AT)wit.ie), Aug 29 2005

CROSSREFS

Sequence in context: A110525 A058859 A095002 * A073516 A005258 A131551

Adjacent sequences:  A080830 A080831 A080832 * A080834 A080835 A080836

KEYWORD

easy,nonn

AUTHOR

Emanuele Munarini (munarini(AT)mate.polimi.it), Mar 28 2003

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Last modified February 17 13:04 EST 2012. Contains 206022 sequences.