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A084900 3^(n-2)n(5n+1)/2. 2
0, 1, 11, 72, 378, 1755, 7533, 30618, 119556, 452709, 1673055, 6062364, 21611934, 75996063, 264126177, 908764110, 3099363912, 10489051017, 35255264499, 117775828656, 391294693890, 1293597012771, 4257363753621, 13954111172802 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

COMMENTS

Binomial transform of A084899. Second binomial transform of heptagonal numbers A000566. Third binomial transform of (0,1,5,0,0,0,....).

LINKS

Table of n, a(n) for n=0..23.

Index entries for linear recurrences with constant coefficients, signature (9,-27,27).

FORMULA

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

MATHEMATICA

Table[(3^(n-2) n(5n+1))/2, {n, 0, 30}] (* or *) LinearRecurrence[{9, -27, 27}, {0, 1, 11}, 30] (* Harvey P. Dale, Jul 21 2016 *)

CROSSREFS

Cf. A084901.

Sequence in context: A258402 A006975 A260585 * A300968 A218619 A197308

Adjacent sequences:  A084897 A084898 A084899 * A084901 A084902 A084903

KEYWORD

easy,nonn

AUTHOR

Paul Barry, Jun 10 2003

STATUS

approved

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Last modified May 18 19:58 EDT 2021. Contains 344002 sequences. (Running on oeis4.)