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A133730 Jacobsthal sequence A001045 interleaved with alternating sign sequence A033999. 1
1, 0, -1, 1, 1, 1, -1, 3, 1, 5, -1, 11, 1, 21, -1, 43, 1, 85, -1, 171, 1, 341, -1, 683, 1, 1365, -1, 2731, 1, 5461 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,8

LINKS

Table of n, a(n) for n=0..29.

FORMULA

a(2n) = (-1)^n. a(2n+1) = A001045(n). O.g.f.: -(x-1)*(x^2-x-1)/[(2*x^2-1)*(1+x^2)] . a(n) = A133684(n+1)-A133684(n). First differences: a(2n)-a(2n+1) = -2*A001045(n-2) for n>=3; a(2n+1)-a(2n) = 4*A001045(n-2) for n >=2. - R. J. Mathar, Jan 09 2008

CROSSREFS

Sequence in context: A146434 A126213 A146935 * A112031 A146285 A146059

Adjacent sequences:  A133727 A133728 A133729 * A133731 A133732 A133733

KEYWORD

sign

AUTHOR

Paul Curtz, Jan 04 2008

EXTENSIONS

Edited by R. J. Mathar, Jan 09 2008

STATUS

approved

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Last modified February 20 07:58 EST 2018. Contains 299365 sequences. (Running on oeis4.)