OFFSET
0,3
LINKS
G. Nebe, E. M. Rains and N. J. A. Sloane, Self-Dual Codes and Invariant Theory, Springer, Berlin, 2006.
FORMULA
G.f.: u1/u2 where u1 := f(t) + t^41*f(1/t), u2 := (1-t)*(1-t^2)^6*(1-t^4)^7*(1-t^8)^2 and
f(t) := 1 + 14*t^3 + 43*t^4 + 115*t^5 + 334*t^6 + 808*t^7 + 1752*t^8 + 3557*t^9 + 6448*t^10 + 10800*t^11 + 17020*t^12 + 24972*t^13 + 34704*t^14 + 45824*t^15 + 57298*t^16 + 68464*t^17 + 78120*t^18 + 85092*t^19 + 88922*t^20.
MAPLE
f := 1 + 14*t^3 + 43*t^4 + 115*t^5 + 334*t^6 + 808*t^7 + 1752*t^8 + 3557*t^9 + 6448*t^10 + 10800*t^11 + 17020*t^12 + 24972*t^13 + 34704*t^14 + 45824*t^15 + 57298*t^16 + 68464*t^17 + 78120*t^18 + 85092*t^19 + 88922*t^20;
u1 := f + t^41*subs(t=1/t, f); u2 := (1-t)*(1-t^2)^6*(1-t^4)^7*(1-t^8)^2;
seq(coeff(series(u1/u2, t, n+1), t, n), n = 0..45); # Georg Fischer, Jan 25 2021
CROSSREFS
KEYWORD
nonn
AUTHOR
G. Nebe (nebe(AT)math.rwth-aachen.de), Nov 10, 2004
STATUS
approved