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A154992 A048473 prefixed by two zeros. 2
0, 0, 1, 5, 17, 53, 161, 485, 1457, 4373, 13121, 39365, 118097, 354293, 1062881, 3188645, 9565937, 28697813, 86093441, 258280325, 774840977, 2324522933, 6973568801, 20920706405, 62762119217, 188286357653, 564859072961 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,4

COMMENTS

Consider two generic sequences correlated via c(n)=b(n) mod p. The difference d(n)=b(n)-c(n) contains only multiples of p and a(n)=d(n)/p defines another integer sequence. This sequence here takes b(n)=A048473(n) with p=9, such that c(n)=1,5,8,8,8,.. (period 8 continued). Then d(n)= 0,0,9,45,153,477,1449,.. becomes 9 times (two zeros followed by A048473) and division through 9 generates a(n) as the shifted version of b(n)=A048374(n).

LINKS

G. C. Greubel, Table of n, a(n) for n = 0..1000

FORMULA

a(n) = A048473(n-2) = 3*2^(n-2)-1, n>1. - R. J. Mathar, Jan 23 2009

G.f.: (x^3 + x^2)/(3*x^2 - 4*x + 1). - Alexander R. Povolotsky, Feb 21 2009

MATHEMATICA

CoefficientList[Series[(x^3 + x^2)/(3*x^2 - 4*x + 1), {x, 0, 50}], x] (* G. C. Greubel, Feb 21 2017 *)

PROG

(PARI) x='x+O('x^50); Vec((x^3 + x^2)/(3*x^2 - 4*x + 1)) \\ G. C. Greubel, Feb 21 2017

CROSSREFS

Sequence in context: A027028 A176086 A048473 * A178828 A242429 A097160

Adjacent sequences:  A154989 A154990 A154991 * A154993 A154994 A154995

KEYWORD

nonn,less

AUTHOR

Paul Curtz, Jan 18 2009

EXTENSIONS

Edited and extended by R. J. Mathar, Jan 23 2009

STATUS

approved

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Last modified October 22 22:58 EDT 2018. Contains 316518 sequences. (Running on oeis4.)