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The odd bisection of A000594.
2

%I #20 Nov 02 2019 02:58:38

%S 1,252,4830,-16744,-113643,534612,-577738,1217160,-6905934,10661420,

%T -4219488,18643272,-25499225,-73279080,128406630,-52843168,134722224,

%U -80873520,-182213314,-145589976,308120442,-17125708,-548895690,2687348496,-1696965207,-1740295368,-1596055698

%N The odd bisection of A000594.

%H Seiichi Manyama, <a href="/A099059/b099059.txt">Table of n, a(n) for n = 0..10000</a>

%H Mathew Rogers, <a href="https://arxiv.org/abs/1210.1942">Identities for the Ramanujan zeta function</a>, arXiv:1210.1942 [math.NT], 2012-2013. See page 3 Lemma 1.

%F Expansion of (F(q) - F(-q)) / 2 = F(q) + 24*F(q^2) + 2048*F(q^4) in powers of q^2 where F() is the g.f. of A000594. - _Michael Somos_, Apr 17 2015

%F a(n) = A000594(2*n + 1). - _Michael Somos_, Apr 17 2015

%e G.f. = 1 + 252*x + 4830*x^2 - 16744*x^3 - 113643*x^4 + 534612*x^5 + ...

%e G.f. = q + 252*q^3 + 4830*q^5 - 16744*q^7 - 113643*q^9 + 534612*q^11 + ...

%t a[ n_] := SeriesCoefficient[ q QPochhammer[q]^24, {q, 0, 2 n + 1}]; (* _Michael Somos_, Apr 17 2015 *)

%o (PARI) {a(n) = if( n<0, 0, n = 2*n+1; polcoeff( x * eta(x + x * O(x^n))^24, n))}; /* _Michael Somos_, Apr 17 2015 */

%Y Cf. A000594.

%K sign

%O 0,2

%A _N. J. A. Sloane_, Nov 15 2004

%E More terms from _Joshua Zucker_, May 15 2006