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A133124 A007318 * [1, 2, 2, 3, 2, 3, 2, 3, 2,...]. 2
1, 3, 7, 16, 35, 74, 153, 312, 631, 1270 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

Table of n, a(n) for n=0..9.

FORMULA

Binomial transform of [1, 2, 2, 3, 2, 3, 2, 3, 2,...]. a(n) = 2^(n+1) + 2^(n-1) - (n+1).

Row sums of triangle A133938. - Gary W. Adamson, Sep 29 2007

G.f.: 1-x*(3-5*x+3*x^2)/(-1+x)^2/(-1+2*x). - R. J. Mathar, Nov 14 2007

EXAMPLE

a(3) = (1, 3, 3, 1) dot (1, 2, 2, 3) = (1 + 6 + 6 + 3).

a(5) = 74 = 2^6 + 2^4 - 6 = 64 + 16 - 6.

CROSSREFS

Cf. A000079.

Cf. A133938.

Sequence in context: A240740 A239257 A238913 * A104004 A101509 A240741

Adjacent sequences:  A133121 A133122 A133123 * A133125 A133126 A133127

KEYWORD

nonn

AUTHOR

Gary W. Adamson, Sep 19 2007

STATUS

approved

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Last modified December 17 18:04 EST 2014. Contains 252034 sequences.