A091972 - OEIS

A091972

G.f.: (1 + x^5 ) / ( (1-x^3)*(1-x^4)).

1, 0, 0, 1, 1, 1, 1, 1, 2, 2, 1, 2, 3, 2, 2, 3, 3, 3, 3, 3, 4, 4, 3, 4, 5, 4, 4, 5, 5, 5, 5, 5, 6, 6, 5, 6, 7, 6, 6, 7, 7, 7, 7, 7, 8, 8, 7, 8, 9, 8, 8, 9, 9, 9, 9, 9, 10, 10, 9, 10, 11, 10, 10, 11, 11, 11, 11, 11, 12, 12, 11, 12, 13, 12, 12, 13, 13, 13, 13, 13, 14, 14, 13, 14, 15, 14, 14, 15, 15, 15

(list; graph; refs; listen; history; text; internal format)

OFFSET

0,9

COMMENTS

Poincaré series [or Poincare series] (or Molien series) for Mathieu group M_11.

REFERENCES

A. Adem and R. J. Milgram, Cohomology of Finite Groups, Springer-Verlag, 2nd. ed., 2004; p. 247.

LINKS

Table of n, a(n) for n=0..89.

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

FORMULA

a(0)=1, a(1)=0, a(2)=0, a(3)=1, a(4)=1, a(5)=1, a(n)=a(n-1)-a(n-2)+ 2*a(n-3)- a(n-4)+a(n-5)-a(n-6). - Harvey P. Dale, Dec 11 2012

G.f.: ( 1-x^3-x+x^2+x^4 ) / ( (x^2+1)*(1+x+x^2)*(x-1)^2 ). - R. J. Mathar, Sep 27 2014

MATHEMATICA

CoefficientList[Series[(1+x^5)/((1-x^3)(1-x^4)), {x, 0, 90}], x] (* or *) LinearRecurrence[{1, -1, 2, -1, 1, -1}, {1, 0, 0, 1, 1, 1}, 90] (* Harvey P. Dale, Dec 11 2012 *)

CROSSREFS

Sequence in context: A238885 A023566 A090970 * A025833 A200647 A261625

Adjacent sequences: A091969 A091970 A091971 * A091973 A091974 A091975

KEYWORD

nonn,easy

AUTHOR

N. J. A. Sloane, Mar 18 2004

STATUS

approved