A099060 The even bisection of A000594.

-24, -1472, -6048, 84480, -115920, -370944, 401856, 987136, 2727432, -7109760, -12830688, 21288960, 13865712, 24647168, -29211840, -196706304, 165742416, 167282496, -255874080, 408038400, 101267712, -786948864, -447438528, 248758272, 611981400, 850430336, 1758697920

Offset: 1

Author

N. J. A. Sloane, Nov 15 2004

Keywords

• sign

Examples

			G.f. = -24*x - 1472*x^2 - 6048*x^3 + 84480*x^4 - 115920*x^5 - 370944*x^6 + ...
G.f. = -24*q^2 - 1472*q^4 - 6048*q^6 + 84480*q^8 - 115920*q^10 - 370944*q^12 + ...
		

Links

• Amiram Eldar, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A000594, A099059.

Programs

Mathematica

a[ n_] := SeriesCoefficient[ q QPochhammer[q]^24, {q, 0, 2 n}]; (* Michael Somos, Apr 17 2015 *)
a[n_] := RamanujanTau[2*n]; Array[a, 30] (* Amiram Eldar, Jan 10 2025 *)

PARI

{a(n) = if( n<0, 0, n = 2*n; polcoeff( x * eta(x + x * O(x^n))^24, n))}; /* Michael Somos, Apr 17 2015 */

Formula

a(n) = A000594(2*n). - Michael Somos, Apr 17 2015

Extensions

More terms from Joshua Zucker, May 15 2006