A008429 -id:A008429 - cp's OEIS frontend

A008435 Theta series of {D_7}^{+} packing.

1, 0, 0, 0, 0, 0, 0, 64, 84, 0, 0, 0, 0, 0, 0, 448, 574, 0, 0, 0, 0, 0, 0, 1344, 1288, 0, 0, 0, 0, 0, 0, 2688, 3444, 0, 0, 0, 0, 0, 0, 4928, 4424, 0, 0, 0, 0, 0, 0, 8064, 9240, 0, 0, 0, 0, 0, 0, 11200, 11088, 0, 0, 0

Offset: 0

N. J. A. Sloane

			G.f.: 1 + 64*q^(7/4) + 84*q^2 + 448*q^(15/4) + 574*q^4 + ... .

J. H. Conway and N. J. A. Sloane, "Sphere Packings, Lattices and Groups", Springer-Verlag, p. 120.

Seiichi Manyama, Table of n, a(n) for n = 0..10000
Eric Weisstein's World of Mathematics, Jacobi Theta Functions

Cf. A008429.

From Seiichi Manyama, Oct 21 2018: (Start)
Expansion of (theta_2(q)^7 + theta_3(q)^7 + theta_4(q)^7)/2 in powers of q^(1/4).
Expansion of (Sum_{k=-inf..inf} q^((k+1/2)^2))^7 + (Sum_{k=-inf..inf} q^(k^2))^7 + (Sum_{k=-inf..inf} (-1)^k * q^(k^2))^7 in powers of q^(1/4). (End)

A297331 Square array A(n,k), n >= 0, k >= 0, read by antidiagonals, where column k is the expansion of (theta_3(q^(1/2))^k + theta_4(q^(1/2))^k)/2.

Original entry on oeis.org

1, 1, 0, 1, 0, 0, 1, 4, 2, 0, 1, 12, 4, 0, 0, 1, 24, 6, 0, 0, 0, 1, 40, 24, 24, 4, 0, 0, 1, 60, 90, 96, 12, 8, 0, 0, 1, 84, 252, 240, 24, 24, 0, 0, 0, 1, 112, 574, 544, 200, 144, 8, 0, 2, 0, 1, 144, 1136, 1288, 1020, 560, 96, 48, 4, 0, 0, 1, 180, 2034, 3136, 3444, 1560, 400, 192, 6, 4, 0, 0

Offset: 0

Ilya Gutkovskiy, Dec 28 2017

			Square array begins:
1,  1,  1,   1,    1,    1,  ...
0,  0,  4,  12,   24,   40,  ...
0,  2,  4,   6,   24,   90,  ...
0,  0,  0,  24,   96,  240,  ...
0,  0,  4,  12,   24,  200,  ...
0,  0,  8,  24,  144,  560,  ...

J. H. Conway and N. J. A. Sloane, Sphere Packings, Lattices and Groups, Springer-Verlag, p. 118.

Columns k=0..32 give A000007, A089798 (absolute values), A004018, A004015, A004011, A005930, A008428, A008429, A008430, A008431, A008432, A022042, A022043, A022044, A022045, A022046, A022047, A022048, A022049, A022050, A022051, A022052, A022053, A022054, A022055, A022056, A022057, A022058, A022059, A022060, A022061, A022062, A022063.
Main diagonal gives A303333.
Cf. A122141, A286815.

Table[Function[k, SeriesCoefficient[(EllipticTheta[3, 0, q^(1/2)]^k + EllipticTheta[4, 0, q^(1/2)]^k)/2, {q, 0, n}]][j - n], {j, 0, 11}, {n, 0, j}] // Flatten

G.f. of column k: (theta_3(q^(1/2))^k + theta_4(q^(1/2))^k)/2, where theta_() is the Jacobi theta function.

cp's OEIS Frontend

A008435 Theta series of {D_7}^{+} packing.

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