A288578 q-Expansion of wedge character chi^(2)(q).

1, 2, 5, 9, 18, 31, 55, 91, 151, 240, 381, 587, 900, 1352, 2018, 2966, 4332, 6250, 8962, 12725, 17962, 25147, 35015, 48414, 66603, 91071, 123945, 167786, 226154, 303375, 405337, 539249, 714740, 943659, 1241605, 1627812, 2127302, 2770966, 3598567

Offset: 0

Author

N. J. A. Sloane, Jul 01 2017

Keywords

• nonn

Links

• Shouvik Datta, M. R. Gaberdiel, W. Li, C. Peng, Twisted sectors from plane partitions, arXiv preprint arXiv:1606.07070 [hep-th], 2016. See Sect. 2.1.

Crossrefs

Cf. A006330 (chi^(0)(q)), A001523 (chi^(1)(q)).

Programs

Maple

chi := proc(l,e)
    local gf,m,n,f;
    gf := 0 ;
    for m from 0 to e+1 do
        f := 1;
        for n from 1 to min(m+abs(l),e-m+1) do
            f := f/(1-q^n) ;
        end do:
        for n from 1 to min(m,e-m+1) do
            f := f/(1-q^n) ;
        end do:
        gf := gf+f*q^m ;
    end do:
    expand(gf) ;
    coeftayl(%,q=0,e) ;
end proc:
A288578 := proc(n)
    chi(2,n) ;
end proc:
for n from 0 do
    printf("%d,\n",A288578(n)) ;
end do: # R. J. Mathar, Jul 04 2017