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A127902 Series reversion of x/(1+x+x^4). 0
1, 1, 1, 1, 2, 6, 16, 36, 75, 163, 391, 991, 2498, 6150, 15016, 37116, 93481, 238137, 607921, 1550401, 3959335, 10155615, 26182267, 67753907, 175713561, 456422121, 1187771521 (list; graph; refs; listen; history; internal format)
OFFSET

0,5

COMMENTS

Binomial transform of A002293, with three interpolated zeros (series reversion of x/(1+x^4)).

FORMULA

a(n)=sum{k=0..floor(n/4), C(n,4k)*C(4k,k)/(3k+1)}

CROSSREFS

Sequence in context: A005676 A038503 A079990 * A157136 A178523 A053210

Adjacent sequences:  A127899 A127900 A127901 * A127903 A127904 A127905

KEYWORD

easy,nonn

AUTHOR

Paul Barry (pbarry(AT)wit.ie), Feb 05 2007

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Last modified February 15 14:57 EST 2012. Contains 205823 sequences.