A025788 - OEIS

A025788

Expansion of 1/((1-x)(1-x^7)(1-x^12)).

1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 3, 3, 4, 4, 4, 4, 4, 5, 5, 6, 6, 6, 7, 7, 8, 8, 9, 9, 9, 10, 10, 11, 11, 12, 13, 13, 14, 14, 15, 15, 16, 17, 17, 18, 18, 19, 20, 21, 22, 22, 23, 23, 24, 25, 26, 27, 27, 28, 29, 30, 31, 32, 33

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OFFSET

0,8

LINKS

Table of n, a(n) for n=0..64.

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

FORMULA

a(0)=1, a(1)=1, a(2)=1, a(3)=1, a(4)=1, a(5)=1, a(6)=1, a(7)=2, a(8)=2, a(9)=2, a(10)=2, a(11)=2, a(12)=3, a(13)=3, a(14)=4, a(15)=4, a(16)=4, a(17)=4, a(18)=4, a(19)=5, a(n)=a(n-1)+a(n-7)-a(n-8)+a(n-12)-a(n-13)- a(n-19)+ a(n-20). - Harvey P. Dale, Jul 29 2013

MATHEMATICA

CoefficientList[Series[1/((1-x)(1-x^7)(1-x^12)), {x, 0, 80}], x] (* or *) LinearRecurrence[{1, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, -1, 1}, {1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 3, 3, 4, 4, 4, 4, 4, 5}, 80] (* Harvey P. Dale, Jul 29 2013 *)

CROSSREFS

Sequence in context: A336014 A304884 A286707 * A071806 A025781 A218379

Adjacent sequences: A025785 A025786 A025787 * A025789 A025790 A025791

KEYWORD

nonn

AUTHOR

N. J. A. Sloane.

STATUS

approved