A335688 Numerator of b(n), where b(1)=b(2)=1, and for n>2, b(n) = (1+b(n-2))/b(n-1).

1, 1, 2, 1, 3, 2, 6, 5, 126, 115, 297108, 1370225, 200590993732752, 531984953824739375, 27113273919595441588692453206842987776, 56653874513318656544104537473266204894369805859375

Offset: 1

Author

N. J. A. Sloane, Jul 17 2020

Keywords

• nonn
• frac

Comments

With a tiny change in subscripts {b(n)} becomes the Lyness 5-cycle, a sequence of period 5, as illustrated in A076839.

Examples

			1, 1, 2, 1, 3, 2/3, 6, 5/18, 126/5, 115/2268, 297108/575, 1370225/673840944, 200590993732752/787879375, ...
		

Crossrefs

Cf. A076839, A335689.