A170910 Write exp(-x) = Product_{n>=1} (1 + g_n * x^n); a(n) = numerator(g_n).

-1, 1, 1, 3, 1, 13, 1, 27, 8, 91, 1, 1213, 1, 505, 1919, 2955, 1, 24557, 1, 1136313, 34943, 12277, 1, 65978519, 624, 57331, 58528, 195948483, 1, 1052424027703, 1, 77010795, 7085759, 1179631, 37497599, 7047825380633, 1, 5242861, 89281919, 355723139681937

Offset: 1

Author

N. J. A. Sloane, Jan 30 2010

Keywords

• sign
• frac

Examples

			-1, 1/2, 1/3, 3/8, 1/5, 13/72, 1/7, 27/128, 8/81, 91/800, 1/11, ...
		

Links

• H. Gingold, H. W. Gould, and Michael E. Mays, Power Product Expansions, Utilitas Mathematica 34 (1988), 143-161.
• G. Helms, A dream of a (number-) sequence

Crossrefs

Cf. A170911 (denominators).

Programs

Maple

L:=100; t1:=exp(-x); t0:=series(t1,x,L): g:=[]; M:=40; t2:=t0:
for n from 1 to M do t3:=coeff(t2,x,n); t2:=series(t2/(1+t3*x^n),x,L); g:=[op(g),t3]; od: g;