A299993 Coefficients in expansion of (E_4^3/E_6^2)^(1/9).

1, 192, 41472, 18342144, 7524397056, 3440911653504, 1589472997005312, 756816895536990720, 364982499184388898816, 178417371665487543380928, 88017286719942539086814208, 43770603489875525093472688896, 21905830503405563891572154843136

Offset

0,2

Links

Seiichi Manyama, Table of n, a(n) for n = 0..367

Formula

Convolution inverse of A299863.

a(n) ~ 2^(8/9) * Pi^(2/3) * exp(2*Pi*n) / (3^(1/9) * Gamma(2/9) * Gamma(1/4)^(8/9) * n^(7/9)). - Vaclav Kotesovec, Mar 04 2018

a(n) * A299863(n) ~ -2*sin(2*Pi/9) * exp(4*Pi*n) / (9*Pi*n^2). - Vaclav Kotesovec, Mar 04 2018

Mathematica

terms = 13;
E4[x_] = 1 + 240*Sum[k^3*x^k/(1 - x^k), {k, 1, terms}];
E6[x_] = 1 - 504*Sum[k^5*x^k/(1 - x^k), {k, 1, terms}];
(E4[x]^3/E6[x]^2)^(1/9) + O[x]^terms // CoefficientList[#, x]& (* Jean-François Alcover, Feb 28 2018 *)

Crossrefs

(E_4^3/E_6^2)^(k/288): A289365 (k=1), A299694 (k=2), A299696 (k=3), A299697 (k=4), A299698 (k=6), A299943 (k=8), A299949 (k=9), A289369 (k=12), A299950 (k=16), A299951 (k=18), A299953 (k=24), this sequence (k=32), A299994 (k=36), A300052 (k=48), A300053 (k=72), A300054 (k=96), A300055 (k=144), A289209 (k=288).

Cf. A004009 (E_4), A013973 (E_6), A299863.

Sequence in context: A001290 A187168 A078272 * A208444 A146554 A183701

Adjacent sequences: A299990 A299991 A299992 * A299994 A299995 A299996

Keyword

nonn

Author

Seiichi Manyama, Feb 22 2018

Status

approved