A331769 El Gradechi's hybrid coefficients alpha^{4,6}_n.

-264, -3456, 0, -23520, 12600, -88704, 68544, -250560, 225720, -591360, 576576, -1231776, 1255800, -2338560, 2448000, -4132224, 4395384, -6894720, 7405440, -10977120, 11858616, -16807296, 18216000, -24897600, 27027000, -35852544, 38937024, -50376480, 54695160, -69281280, 75161856

Offset

0,1

Comments

See El Gradechi (2013) for precise definition.

Links

Robin Visser, Table of n, a(n) for n = 0..10000

Amine M. El Gradechi, The Lie theory of certain modular form and arithmetic identities, The Ramanujan Journal 31.3 (2013): 397-433.

Index entries for linear recurrences with constant coefficients, signature (-2,3,8,-2,-12,-2,8,3,-2,-1).

Formula

a(n) = (-1)^n*240*binomial(n+5, 5) - 504*binomial(n+3, 3). - Robin Visser, Jul 29 2023

G.f.: -24*(11 + 166*x + 255*x^2 + 460*x^3 + 305*x^4 + 126*x^5 + 21*x^6)/((1 - x)^4*(1 + x)^6). - Andrew Howroyd, Nov 14 2025

Prog

(Magma) [(-1)^n*240*Binomial(n+5, 5)-504*Binomial(n+3, 3): n in [0..100]]; // Robin Visser, Jul 29 2023
(PARI) a(n) = (-1)^n*240*binomial(n+5, 5)-504*binomial(n+3, 3); \\ Robin Visser, Jul 29 2023

Crossrefs

Cf. A331768, A331770.

Sequence in context: A004533 A231301 A211718 * A288995 A092724 A112069

Adjacent sequences: A331766 A331767 A331768 * A331770 A331771 A331772

Keyword

sign

Author

N. J. A. Sloane, Feb 08 2020

Extensions

More terms from Robin Visser, Jul 29 2023

Status

approved