A256400 Numerators of coefficients of expansion of exp( Sum_{k=0..oo} x^(2^k)/2^k ) in powers of x.

1, 1, 1, 2, 2, 7, 16, 67, 88, 617, 2626, 18176, 6949, 423271, 2172172, 19151162, 58438907, 899510224, 7656246634, 1236339998, 460251204914, 6682341795214, 55431849118769, 58399157390146, 2845938531282919, 54648005951674444, 12207653488921678

Offset: 0

Author

N. J. A. Sloane, Mar 29 2015

Keywords

• nonn
• frac

Links

• Hiroaki Yamanouchi, Table of n, a(n) for n = 0..100
• Koda, Tatsuhiko; Sato, Masaki; Takegahara, Yugen; 2-adic properties for the numbers of involutions in the alternating groups, J. Algebra Appl. 14 (2015), no. 4, 1550052 (21 pages). See Lemma 2.1.

Crossrefs

For denominators see A049606. Cf. A256401/A256402.

Extensions

a(18)-a(26) from Hiroaki Yamanouchi, Mar 30 2015