OFFSET
0,2
LINKS
G. C. Greubel, Table of n, a(n) for n = 0..1000
FORMULA
G.f.: P_6(x) / ((1-x)*(1-x^2)*(1-x^3)*(1-x^4)*(1-x^5)*(1-x^6))^2, with P_6(1) = 11!, where P_6(x) = (1+5*x+85*x^2+581*x^3+2763*x^4+9987*x^5+29644*x^6+74546*x^7+ 164629*x^8+324255*x^9+579250*x^10+946960*x^11+1429875*x^12+2003713*x^13+ 2620218*x^14+3205496*x^15+3679773*x^16+3967701*x^17+4024087*x^18+ 3837087*x^19+3440204*x^20+2894878*x^21+2283089*x^22+1681653*x^23+ 1153208*x^24+731684*x^25+427027*x^26+226843*x^27+108486*x^28+45806*x^29+ 16737*x^30+5073*x^31+1221*x^32+211*x^33+23*x^34+x^35).
PROG
(PARI) {a(n)=polcoeff(truncate(Ser([1, 5, 85, 581, 2763, 9987, 29644, 74546, 164629, 324255, 579250, 946960, 1429875, 2003713, 2620218, 3205496, 3679773, 3967701, 4024087, 3837087, 3440204, 2894878, 2283089, 1681653, 1153208, 731684, 427027, 226843, 108486, 45806, 16737, 5073, 1221, 211, 23, 1])) / ((1-x)^2*(1-x^2)^2*(1-x^3)^2*(1-x^4)^2*(1-x^5)^2*(1-x^6)^2 +x*O(x^n)), n)}
CROSSREFS
KEYWORD
nonn
AUTHOR
Paul D. Hanna, Oct 03 2006
STATUS
approved