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A015511 a(1)=1, a(n) = sum_{k=1}^{k=n-1} (9^k-1)/8 a(k). 0
1, 1, 11, 1012, 830852, 6133349464, 407444538242984, 243599680968409330048, 1310771150941736627904810368, 63477451180042308935531134194562816, 27666523379269090447091129488519658150671616 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

LINKS

Table of n, a(n) for n=1..11.

FORMULA

a(n) = ((9^(n-1) + 7)/8) * a(n-1). - Vincenzo Librandi, Nov 12 2012

PROG

(MAGMA) I:=[1, 1, 11]; [n le 3 select I[n] else ((9^(n-1) + 7)/8) * Self(n-1): n in [1..15]]; // Vincenzo Librandi, Nov 12 2012

CROSSREFS

Sequence in context: A127962 A267606 A303786 * A065050 A099440 A073903

Adjacent sequences:  A015508 A015509 A015510 * A015512 A015513 A015514

KEYWORD

nonn,easy

AUTHOR

Olivier Gérard

STATUS

approved

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Last modified October 19 21:50 EDT 2021. Contains 348095 sequences. (Running on oeis4.)