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A182512 a(n) = (16^n - 1)/5. 3
0, 3, 51, 819, 13107, 209715, 3355443, 53687091, 858993459, 13743895347, 219902325555, 3518437208883, 56294995342131, 900719925474099, 14411518807585587, 230584300921369395, 3689348814741910323, 59029581035870565171, 944473296573929042739 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

Even bisection of A015521 and also A112627. All of the terms are divisible by 3, even terms by 17.

LINKS

Robert Israel, Table of n, a(n) for n = 0..830

E. Estrada and J. A. de la Pena, From Integer Sequences to Block Designs via Counting Walks in Graphs, arXiv preprint arXiv:1302.1176 [math.CO], 2013. - From N. J. A. Sloane, Feb 28 2013

E. Estrada and J. A. de la Pena, Integer sequences from walks in graphs, Notes on Number Theory and Discrete Mathematics, Vol. 19, 2013, No. 3, 78-84

Index entries for linear recurrences with constant coefficients, signature (17,-16)

FORMULA

a(n) = 16*a(n-1) + 3 where a(0)=0.

a(n) = A015521(2n), n=0,1,2...

a(n) = A112627(2n), n=1,2,3... and a(0)=0.

G.f.: 3*x / ( (16*x-1)*(x-1) ). - R. J. Mathar, Apr 20 2015

a(n) = 3*A131865(n-1). - R. J. Mathar, Apr 20 2015

MAPLE

seq((16^n-1)/5, n=0..50); # Robert Israel, Jan 22 2016

PROG

(MAGMA)[(1/5)*2^(4*i) -(1/5): i in [0..30]];

(PARI) a(n) = (16^n - 1)/5; \\ Michel Marcus, Jan 22 2016

CROSSREFS

Cf. A015521, A112627.

Sequence in context: A232453 A248341 A145242 * A075869 A307369 A126685

Adjacent sequences:  A182509 A182510 A182511 * A182513 A182514 A182515

KEYWORD

nonn,easy

AUTHOR

Brad Clardy, May 03 2012

STATUS

approved

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Last modified July 21 21:14 EDT 2019. Contains 325199 sequences. (Running on oeis4.)