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A113282 Logarithmic derivative of the g.f. of A113281. 4
1, 5, 7, 17, 41, 101, 239, 577, 1393, 3365, 8119, 19601, 47321, 114245, 275807, 665857, 1607521, 3880901, 9369319, 22619537, 54608393, 131836325, 318281039, 768398401, 1855077841, 4478554085, 10812186007, 26102926097, 63018038201 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

Table of n, a(n) for n=0..28.

FORMULA

G.f.: (1+x^2)/(1-x^2)/(1-2*x-x^2) + x*(3+x^2)/(1-x^4). a(2*n) = A113224(2*n), a(4*n+1) = 3 + A113224(4*n+1), a(4*n+3) = 1 + A113224(4*n+3), where A113224 is the self-convolution of A113281.

a(n) ~ (1 + sqrt(2))^(n+1) / 2. - Vaclav Kotesovec, Oct 18 2020

PROG

(PARI) {a(n)=local(x=X+X*O(X^n)); polcoeff((1+x^2)/(1-x^2)/(1-2*x-x^2) + x*(3+x^2)/(1-x^4), n, X)}

CROSSREFS

Cf. A113281, A113283, A113284.

Sequence in context: A318568 A239414 A163570 * A323200 A096741 A106955

Adjacent sequences:  A113279 A113280 A113281 * A113283 A113284 A113285

KEYWORD

nonn

AUTHOR

Paul D. Hanna, Oct 22 2005

STATUS

approved

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Last modified December 4 13:03 EST 2021. Contains 349526 sequences. (Running on oeis4.)