A075108 First integer reached when starting with n/floor(log_2(n)) and iterating the map x -> x*ceiling(x) A075107(n) times, or -1 if no integer is ever reached.

2, 3, 2, 60, 3, 14, 8, 3, 1484710602474311520, 220, 4, 227370, 560, 5, 4, 218790, 268065, 570, 5, 1008, 33, 1458660, 6, 1925, 2093, 2268, 7, 58, 60, 62, 2016, 494764640798827359861461484, 5220768, 7

Offset

2,1

Links

Table of n, a(n) for n=2..35.

Example

n=5: after A075107(5)=2 steps 5/floor(log_2(5)) = 5/2 -> 15/2 -> 60, therefore a(5)=60.

Crossrefs

Cf. A075103, A075121.

Sequence in context: A369190 A291489 A075121 * A364139 A265590 A260208

Adjacent sequences: A075105 A075106 A075107 * A075109 A075110 A075111

Keyword

nonn

Author

Reinhard Zumkeller, Sep 02 2002

Status

approved