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A098483 Expansion of 1/sqrt((1-x)^2-8x^4). 2
1, 1, 1, 1, 5, 13, 25, 41, 85, 205, 473, 985, 2021, 4365, 9785, 21673, 46965, 101581, 222745, 492665, 1087237, 2388749, 5251065, 11587529, 25633045, 56697933, 125345113, 277283353, 614212133, 1361824525, 3020426681, 6700678377 (list; graph; refs; listen; history; internal format)
OFFSET

0,5

COMMENTS

1/sqrt((1-x)^2-4rx^4) expands to sum{k=0..floor(n/2), binomial(n-2k,k)binomial(n-3k,k)r^k}

FORMULA

a(n)=sum{k=0..floor(n/2), binomial(n-2k, k)binomial(n-3k, k)2^k}

CROSSREFS

Cf. A098480, A098482, A098484.

Sequence in context: A099776 A133322 A146590 * A147205 A146875 A064276

Adjacent sequences:  A098480 A098481 A098482 * A098484 A098485 A098486

KEYWORD

easy,nonn

AUTHOR

Paul Barry (pbarry(AT)wit.ie), Sep 10 2004

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Last modified February 15 11:25 EST 2012. Contains 205777 sequences.