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A085287 Expansion of (1+4x)/((1-x^2)(1-3x)). 2
1, 7, 22, 70, 211, 637, 1912, 5740, 17221, 51667, 155002, 465010, 1395031, 4185097, 12555292, 37665880, 112997641, 338992927, 1016978782, 3050936350, 9152809051, 27458427157, 82375281472, 247125844420, 741377533261, 2224132599787, 6672397799362, 20017193398090 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

Binomial transform of A084431.

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 0..1000

FORMULA

a(n) = (-10 - 3(-1)^n + 21*3^n)/8.

a(n) = 2*a(n-1) + 3*a(n-2) + 5, a(0)=0, a(1)=1. [Zerinvary Lajos, Dec 14 2008]

MAPLE

a[0]:=0:a[1]:=1:for n from 2 to 50 do a[n]:=2*a[n-1]+3*a[n-2]+5 od: seq(a[n], n=1..33); # Zerinvary Lajos, Dec 14 2008

PROG

(MAGMA) [(-10-3*(-1)^n+21*3^n)/8: n in [0..30]]; // Vincenzo Librandi, Nov 16 2011

(PARI) Vec((1+4*x)/((1-x^2)*(1-3*x)) + O(x^30)) \\ Michel Marcus, Aug 14 2017

CROSSREFS

Sequence in context: A246831 A122238 A101289 * A278767 A286186 A282035

Adjacent sequences:  A085284 A085285 A085286 * A085288 A085289 A085290

KEYWORD

easy,nonn

AUTHOR

Paul Barry, Jun 26 2003

STATUS

approved

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Last modified May 14 22:40 EDT 2021. Contains 343909 sequences. (Running on oeis4.)