A028525 Character of extremal vertex operator algebra of rank 15.5.

1, 0, 248, 3875, 31124, 181753, 871627, 3623869, 13496501, 46070247, 146447007, 438436131, 1246840863, 3390992753, 8867414995, 22393107641, 54807572758, 130403285724, 302393467628, 684927912490, 1518200420906, 3298704166389, 7035880460575, 14750661826629

Offset

0,3

References

G. Hoehn, Selbstduale Vertexoperatorsuperalgebren und das Babymonster, Bonner Mathematische Schriften, Vol. 286 (1996), 1-85.

Links

Table of n, a(n) for n=0..23.

G. Hoehn (gerald(AT)math.ksu.edu), Selbstduale Vertexoperatorsuperalgebren und das Babymonster, Doctoral Dissertation, Univ. Bonn, Jul 15 1995 (pdf, ps).

Formula

G.f.: q^(31/24) * (b(q)^31 - 31*b(q)^7) where b(q) = q^(-1/24) * Product_{k>=0} (1+q^(2*k+1)). - Sean A. Irvine, Feb 04 2020

a(n) ~ 31^(1/4) * exp(Pi*sqrt(31*n/6)) / (2^(7/4) * 3^(1/4) * n^(3/4)). - Vaclav Kotesovec, Feb 05 2020

Mathematica

nmax = 30; CoefficientList[Series[Product[(1 + x^(2*k + 1))^31, {k, 0, nmax}] - 31*x*Product[(1 + x^(2*k + 1))^7, {k, 0, nmax}], {x, 0, nmax}], x] (* Vaclav Kotesovec, Feb 05 2020 *)

Crossrefs

Cf. A007245, A097340, A028523, A028524, A028511, A000521.

Sequence in context: A200426 A109476 A121732 * A135046 A027654 A003916

Adjacent sequences: A028522 A028523 A028524 * A028526 A028527 A028528

Keyword

nonn,easy

Author

N. J. A. Sloane

Extensions

More terms from Sean A. Irvine, Feb 04 2020

Status

approved