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A027209 a(n) = Sum_{k=0..n-2} T(n,k) * T(n,k+2), with T given by A026725. 1
1, 7, 34, 173, 741, 3549, 14670, 68683, 279715, 1294598, 5233060, 24052965, 96822587, 442972139, 1778697948, 8110611295, 32516501991, 147897243768, 592346459071, 2688895275974, 10762289869782, 48776681304283, 195143578562778, 883272843800993, 3532739195660162 (list; graph; refs; listen; history; text; internal format)
OFFSET

2,2

LINKS

Table of n, a(n) for n=2..26.

MAPLE

A027209 := proc(n)

    add( A026725(n, k)*A026725(n, k+2), k=0..n-2) ;

end proc: # R. J. Mathar, Oct 21 2019

CROSSREFS

Sequence in context: A124466 A055271 A209890 * A209807 A080048 A177140

Adjacent sequences:  A027206 A027207 A027208 * A027210 A027211 A027212

KEYWORD

nonn

AUTHOR

Clark Kimberling

EXTENSIONS

Name corrected by R. J. Mathar, Oct 21 2019

More terms from Sean A. Irvine, Oct 24 2019

STATUS

approved

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Last modified September 26 06:16 EDT 2021. Contains 347664 sequences. (Running on oeis4.)