A067654 Numerators of the coefficients in power series expansion of exp(2x/(1-x)).

2, 4, 22, 38, 314, 1504, 16346, 24796, 331906, 2426404, 38445118, 163944598, 2993870654, 2647864592, 601353085846, 820420721222, 18874008233858, 20741357283932, 5782164084903302, 38314394323494974, 1059898973520975218

Offset: 1

Author

Benoit Cloitre, Feb 03 2002

Keywords

• nonn
• frac

References

• K. Knopp, Theory and application of infinite series, Dover, p. 547.
• O. Perron, Über das infinitäre Verhalten der Koeffizienten einer gewissen Potenzreihe, Archiv d. Math. u. Phys. (3), Vol. 22, pp. 329-340, 1914.

Crossrefs

Cf. A067655.

Formula

a(n) is the numerator of Sum_{i=1..n} binomial(n-1, i-1)*2^i/i!.