A027009 - OEIS

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A027009

a(n) = T(n,m) + T(n,m+1) + ... + T(n,n), where m=[ (n+2)/2 ], T given by A026998.

0

1, 1, 9, 14, 46, 81, 209, 389, 901, 1726, 3774, 7349, 15541, 30561, 63329, 125294, 256366, 509161, 1033449, 2057549, 4154701, 8284926, 16673534, 33282989, 66837421, 133507081, 267724809, 535010414, 1071881326, 2142612801

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,3

LINKS

Table of n, a(n) for n=1..30.

FORMULA

G.f.: x(-2x^4-x^3+4x^2-x+1)/[(1-2x)(1+x-x^2)(1-x-x^2)].

CROSSREFS

Sequence in context: A139055 A294030 A079625 * A239038 A271596 A272275

Adjacent sequences: A027006 A027007 A027008 * A027010 A027011 A027012

KEYWORD

nonn

AUTHOR

Clark Kimberling

STATUS

approved