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Search: id:A113726
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A113726 A Jacobsthal convolution. +0
2
1, 0, 1, 4, 5, 8, 25, 44, 77, 176, 353, 660, 1365, 2776, 5417, 10876, 21981, 43648, 87153, 175076, 349669, 698280, 1398585, 2797260, 5590381, 11184720, 22373761, 44735284, 89474165, 178969208, 357910345, 715807004, 1431683837, 2863325216 (list; graph; listen)
OFFSET

0,4

COMMENT

Convolution of A001045(n+1) and A001607(n+1).

FORMULA

G.f.: 1/((1-x-2x^2)(1+x+2x^2)); a(n)=a(n-2)+4a(n-3)+4a(n-4); a(n)=sum{k=0..floor(n/2), C(n-k, k)2^k*(1+(-1)^(n-k))/2}.

CROSSREFS

Cf. A094686, A089977.

Sequence in context: A145265 A072808 A104884 this_sequence A140315 A055497 A093088

Adjacent sequences: A113723 A113724 A113725 this_sequence A113727 A113728 A113729

KEYWORD

easy,nonn

AUTHOR

Paul Barry (pbarry(AT)wit.ie), Nov 08 2005

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Last modified November 18 20:14 EST 2008. Contains 147244 sequences.


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