OFFSET
0,1
LINKS
Paul D. Hanna, Table of n, a(n) for n = 0..380
EXAMPLE
G.f.: A(q) = 2 - 4*q + 8*q^2 - 12*q^3 + 20*q^4 - 44*q^5 + 52*q^6 - 76*q^7 + 136*q^8 - 164*q^9 + 252*q^10 - 396*q^11 + 482*q^12 - 684*q^13 + 990*q^14 - 1272*q^15 + 1748*q^16 - 2388*q^17 + 3038*q^18 - 4020*q^19 + 5358*q^20 +...
MATHEMATICA
nmax = 55; kmax = Ceiling[Sqrt[nmax]]+1;
Q[q_] := Sum[(x - q^k)^k, {k, -kmax, kmax}];
S[q_] := Sqrt[Q[q]/Q[-q]];
row[n_] := (1/q^n)*SeriesCoefficient[Sqrt[Q[q]/Q[-q]], {x, 0, n} ] + O[q]^nmax // CoefficientList[#, q]&;
row[3] (* Jean-François Alcover, Nov 04 2017 *)
CROSSREFS
KEYWORD
sign
AUTHOR
Paul D. Hanna, Oct 23 2017
STATUS
approved