A074923 Number of steps to reach the first integer starting with prime(n+1)/prime(n) and iterating the map x -> x*ceiling(x), or -1 if no integer is ever reached.

1, 6, 18, 5, 5, 7, 37, 132, 29, 63, 46, 11, 7, 212, 25, 38, 145, 136, 46, 118, 39, 37, 24, 15, 19, 85, 211, 179, 249, 266, 190, 87, 259, 216, 16, 70, 210, 56, 255, 94, 143, 244, 482, 558, 46, 327, 271, 93, 110, 8, 121, 29, 421, 329, 47, 40, 394, 376, 64, 249, 49, 390, 321

Offset: 1

Author

Reinhard Zumkeller, Oct 04 2002

Keywords

• nonn

Examples

			a(4)=5 since A000040(4+1)/A000040(4)=11/7 -> 22/7 -> 88/7 -> 1144/7 -> 187616/7 -> 718381664.
		

Links

• Sean A. Irvine, Table of n, a(n) for n = 1..200

Crossrefs

Cf. A073524, A000040.

Extensions

Extended by Max Alekseyev, Jul 28 2009