A107657 Coefficients of 12th root of theta series of lattice in A004046.

1, 0, 0, 2184, 44226, 530712, -22289904, -1041080040, -23414482728, 86664734520, 22704271546320, 824932708688088, 10338270616438674, -363177176817506688, -24534229526034608016, -614775613733783853624, -526997882017733986314, 591470477348411755418688, 24257417213770154760619728, 384176112414487265101313448

Offset: 0

Author

N. J. A. Sloane and Michael Somos, Jun 07 2005

Keywords

• sign

Links

• Vincenzo Librandi, Table of n, a(n) for n = 0..200
• N. Heninger, E. M. Rains and N. J. A. Sloane, On the Integrality of n-th Roots of Generating Functions, J. Combinatorial Theory, Series A, 113 (2006), 1732-1745.

Crossrefs

Cf. A004046.

Programs

Mathematica

terms = 20; QP = QPochhammer; Q9 = (1 + (9*q*QP[q^9]^3)/QP[q]^3); s = (1/(3^(1/4)*QP[q^3]))*QP[q]^3*(-8 + 16*Q9^3 + 64*Q9^6 - 72*Q9^9 + 27*Q9^12)^(1/12) + O[q]^terms; CoefficientList[s, q] (* Jean-François Alcover, Jul 06 2017, after Michael Somos *)