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A025768 Expansion of 1/((1-x)*(1-x^3)*(1-x^7)). 0
1, 1, 1, 2, 2, 2, 3, 4, 4, 5, 6, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 17, 18, 19, 21, 22, 23, 25, 27, 28, 30, 32, 33, 35, 37, 39, 41, 43, 45, 47, 49, 51, 54, 56, 58, 61, 63, 65, 68, 71, 73, 76, 79, 81, 84, 87, 90, 93, 96 (list; graph; refs; listen; history; internal format)
OFFSET

0,4

COMMENTS

(x^4+x^5+x^6+2*x^7+x^8+x^9+x^10) / ((1-x^4)*(1-x^6)*(1-x^7)) is the Poincare series (or Molien series) for (H^*(Q)\otimes St)^(GL_3(F_2)). This gives the same sequence but prefixed by four 0's.

REFERENCES

A. Adem and R. J. Milgram, Cohomology of Finite Groups, Springer-Verlag, 2nd. ed., 2004; p. 259.

L. Comtet, Advanced Combinatorics, Reidel, 1974, p. 120, D(n;1,3,7).

FORMULA

a(n) = round((n+3)*(n+8)/42).

CROSSREFS

Sequence in context: A063124 A070547 A094838 * A000929 A029146 A029053

Adjacent sequences:  A025765 A025766 A025767 * A025769 A025770 A025771

KEYWORD

nonn

AUTHOR

N. J. A. Sloane (njas(AT)research.att.com).

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Last modified February 16 02:51 EST 2012. Contains 205860 sequences.