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A001307 Expansion of 1/(1-x)^2/(1-x^2)/(1-x^4)/(1-x^10)/(1-x^20). 1
1, 2, 4, 6, 10, 14, 20, 26, 35, 44, 57, 70, 88, 106, 130, 154, 185, 216, 255, 294, 344, 394, 456, 518, 595, 672, 765, 858, 970, 1082, 1216, 1350, 1509, 1668, 1855, 2042, 2260, 2478, 2730, 2982, 3274, 3566, 3901, 4236, 4620, 5004, 5440, 5876, 6370, 6864 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

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

INRIA Algorithms Project, Encyclopedia of Combinatorial Structures 200

Index entries for linear recurrences with constant coefficients, signature (2, 0, -2, 2, -2, 0, 2, -1, 0, 1, -2, 0, 2, -2, 2, 0, -2, 1, 0, 1, -2, 0, 2, -2, 2, 0, -2, 1, 0, -1, 2, 0, -2, 2, -2, 0, 2, -1).

FORMULA

G.f.: 1/(1-x)^2/(1-x^2)/(1-x^4)/(1-x^10)/(1-x^20).

MATHEMATICA

CoefficientList[Series[1/(1-x)^2/(1-x^2)/(1-x^4)/(1-x^10)/(1-x^20), {x, 0, 50}], x] (* Vincenzo Librandi, Feb 24 2012 *)

CROSSREFS

Sequence in context: A071425 A115065 A008804 * A088932 A088954 A000123

Adjacent sequences:  A001304 A001305 A001306 * A001308 A001309 A001310

KEYWORD

nonn,easy

AUTHOR

N. J. A. Sloane.

STATUS

approved

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Last modified November 14 04:41 EST 2018. Contains 317161 sequences. (Running on oeis4.)