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A054444 Even indexed members of A001629(n), n >= 2, (Fibonacci convolution). 6
1, 5, 20, 71, 235, 744, 2285, 6865, 20284, 59155, 170711, 488400, 1387225, 3916061, 10996580, 30737759, 85573315, 237387960, 656451269, 1810142185, 4978643596, 13661617195, 37409025455, 102238082976, 278920277425, 759695287349 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

Table of n, a(n) for n=0..25.

É. Czabarka, R. Flórez, L. Junes, A Discrete Convolution on the Generalized Hosoya Triangle, Journal of Integer Sequences, 18 (2015), #15.1.6.

Guo-Niu Han, Enumeration of Standard Puzzles

Guo-Niu Han, Enumeration of Standard Puzzles [Cached copy]

FORMULA

a(n) = ((2*n+1)*F(2*(n+1))+4*(n+1)*F(2*n+1))/5, with F(n)= A000045(n) (Fibonacci numbers).

G.f.: (1-x+x^2)/(1-3*x+x^2)^2.

a(n) = sum(k*binom(2n-2k+2, k), k=1..n+1). - Emeric Deutsch, Jun 11 2003

CROSSREFS

Cf. A001870, A001629, A000045. a(n)= A060920(n+1, 1).

Sequence in context: A054889 A056384 A036683 * A121332 A122695 A269914

Adjacent sequences:  A054441 A054442 A054443 * A054445 A054446 A054447

KEYWORD

easy,nonn

AUTHOR

Wolfdieter Lang, Apr 07 2000

STATUS

approved

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Last modified December 16 09:34 EST 2018. Contains 318160 sequences. (Running on oeis4.)