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A008622
Expansion of 1/((1-x^4)*(1-x^6)*(1-x^7)).
1
1, 0, 0, 0, 1, 0, 1, 1, 1, 0, 1, 1, 2, 1, 2, 1, 2, 1, 3, 2, 3, 2, 3, 2, 4, 3, 4, 3, 5, 3, 5, 4, 6, 4, 6, 5, 7, 5, 7, 6, 8, 6, 9, 7, 9, 7, 10, 8, 11, 9, 11, 9, 12, 10, 13, 11, 14, 11, 14, 12, 16, 13, 16, 14, 17, 14, 18, 16, 19, 16, 20, 17, 21, 18, 22, 19, 23, 20, 24, 21, 25, 22, 26, 23, 28, 24, 28
OFFSET
0,13
COMMENTS
Molien series of 3-dimensional representation of GL(3,2) over GF(2).
REFERENCES
D. J. Benson, Polynomial Invariants of Finite Groups, Cambridge, 1993, p. 106.
LINKS
A. Adem, Recent developments in the cohomology of finite groups, Notices Amer. Math. Soc., 44 (1997), 806-812.
Index entries for linear recurrences with constant coefficients, signature (0,0,0,1,0,1,1,0,0,-1,-1,0,-1,0,0,0,1).
FORMULA
a(0)=1, a(1)=0, a(2)=0, a(3)=0, a(4)=1, a(5)=0, a(6)=1, a(7)=1, a(8)=1, a(9)=0, a(10)=1, a(11)=1, a(12)=2, a(13)=1, a(14)=2, a(15)=1, a(16)=2, a(n)=a(n-4)+a(n-6)+a(n-7)-a(n-10)-a(n-11)-a(n-13)+a(n-17). - Harvey P. Dale, May 09 2013
a(n) ~ 1/336*n^2. - Ralf Stephan, Apr 29 2014
a(n) = floor((n^2+17*n+144)/336 + n*(-1)^n/48 + ((n^2+3*n+4) mod 7)/7). - Hoang Xuan Thanh, Sep 09 2025
MAPLE
1/(1-x^4)/(1-x^6)/(1-x^7);
MATHEMATICA
CoefficientList[Series[1/((1-x^4)(1-x^6)(1-x^7)), {x, 0, 90}], x] (* or *) LinearRecurrence[{0, 0, 0, 1, 0, 1, 1, 0, 0, -1, -1, 0, -1, 0, 0, 0, 1}, {1, 0, 0, 0, 1, 0, 1, 1, 1, 0, 1, 1, 2, 1, 2, 1, 2}, 90] (* Harvey P. Dale, May 09 2013 *)
PROG
(PARI) a(n) = (n^2+17*n+144 + 7*n*(-1)^n + 48*((n^2+3*n+4)%7))\336 \\ Hoang Xuan Thanh, Sep 09 2025
CROSSREFS
Sequence in context: A376798 A388722 A185318 * A029414 A053275 A025816
KEYWORD
nonn,easy
STATUS
approved