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A087213 Expansion of (1+x-4x^2)/((1+x)(1-4x^2)). 0
1, 0, 0, 4, -4, 20, -20, 84, -84, 340, -340, 1364, -1364, 5460, -5460, 21844, -21844, 87380, -87380, 349524, -349524, 1398100, -1398100, 5592404, -5592404, 22369620, -22369620, 89478484, -89478484, 357913940, -357913940, 1431655764, -1431655764 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,4

COMMENTS

Binomial transform is A046717 (with extra leading 1). a(2n+1)=A002450(n)=A001045(2n). a(2n+2)=-A002450(n)=-A001045(2n).

LINKS

Table of n, a(n) for n=0..32.

Index entries for linear recurrences with constant coefficients, signature (-1,4,4).

FORMULA

a(n)=2^n/6-(-2)^n/2+4(-1)^n/3

CROSSREFS

Sequence in context: A264528 A035413 A261568 * A117857 A165559 A180967

Adjacent sequences:  A087210 A087211 A087212 * A087214 A087215 A087216

KEYWORD

easy,sign

AUTHOR

Paul Barry, Aug 26 2003

STATUS

approved

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Last modified December 2 15:01 EST 2016. Contains 278678 sequences.