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El Gradechi's hybrid coefficients alpha^{4,4}_{2n}.
3

%I #21 Jul 29 2023 03:26:48

%S 480,4800,16800,40320,79200,137280,218400,326400,465120,638400,850080,

%T 1104000,1404000,1753920,2157600,2618880,3141600,3729600,4386720,

%U 5116800,5923680,6811200,7783200,8843520,9996000,11244480,12592800,14044800,15604320,17275200,19061280,20966400,22994400

%N El Gradechi's hybrid coefficients alpha^{4,4}_{2n}.

%C See El Gradechi (2013) page 426 for precise definition.

%H Robin Visser, <a href="/A331768/b331768.txt">Table of n, a(n) for n = 0..10000</a>

%H Amine M. El Gradechi, <a href="https://doi.org/10.1007/s11139-012-9415-5">The Lie theory of certain modular form and arithmetic identities</a>, The Ramanujan Journal 31.3 (2013): 397-433.

%F a(n) = 480 * binomial(3 + 2*n, 3) = 480 * A000447(n+1). - _Robin Visser_, Jul 24 2023

%o (Magma) [480*Binomial(3 + 2*n, 3) : n in [0..100]]; // _Robin Visser_, Jul 24 2023

%o (PARI) a(n) = 480*binomial(3 + 2*n, 3); \\ _Robin Visser_, Jul 24 2023

%Y Cf. A000447, A331769, A331770.

%K nonn

%O 0,1

%A _N. J. A. Sloane_, Feb 08 2020

%E More terms from _Robin Visser_, Jul 24 2023