A203811 Denominators of s(i) = s(i-1) - (1/i)*sign(s(i-1)) with s(1) = 1.

1, 2, 6, 12, 60, 20, 140, 280, 2520, 2520, 27720, 27720, 360360, 360360, 72072, 144144, 2450448, 2450448, 46558512, 232792560, 232792560, 232792560, 5354228880, 5354228880, 26771144400, 26771144400, 80313433200, 80313433200, 2329089562800, 2329089562800

Offset: 1

Author

Hugo Pfoertner and Rainer Rosenthal, Jan 06 2012

Keywords

• nonn
• frac

Comments

Numerators are given in A203810. The first 14 terms coincide with those of A002805.

Examples

			See A203810.
		

Links

• Hugo Pfoertner, Table of n, a(n) for n = 1..200

Crossrefs

Cf. A002805, A203810 (numerators), A203812.

Programs

Mathematica

nxt[{n_,a_}]:={n+1,a-1/(n+1) Sign[a]}; NestList[nxt,{1,1},30][[All,2]]//Denominator (* Harvey P. Dale, Jun 06 2021 *)