A081850 Consider recurrence b(0) = (2n+1)/4, b(n) = b(0)*ceiling(b(n-1)); sequence gives number of steps to reach an integer (or -1 if no integer is ever reached).

3, 2, 3, 13, 1, 1, 4, 2, 2, 9, 2, 2, 1, 1, 7, 3, 7, 3, 4, 3, 1, 1, 2, 4, 5, 10, 5, 13, 1, 1, 14, 8, 5, 2, 10, 11, 1, 1, 6, 2, 2, 17, 2, 2, 1, 1, 3, 6, 16, 5, 3, 4, 1, 1, 2, 4, 7, 9, 4, 3, 1, 1, 15, 9, 4, 2, 7, 5, 1, 1, 3, 2, 2, 3, 2, 2, 1, 1, 5, 5, 6, 5, 6, 4, 1, 1, 2, 4, 4, 3, 3, 11, 1, 1, 3, 3, 7, 2, 4

Offset

2,1

Links

Robert Israel, Table of n, a(n) for n = 2..10000

Maple

Digits := 100: c := ceil; A081850 := proc(a) local i, t0, t; t0 := a; t := 0; for i from 1 to 100 do if whattype(t0) <> integer then t0 := a*c(t0); t := t+1; else RETURN(t); fi; od; RETURN('FAIL'); end;

Crossrefs

Cf. A073524, A081849, A081851.

Sequence in context: A169816 A291739 A057053 * A247237 A059366 A298594

Adjacent sequences: A081847 A081848 A081849 * A081851 A081852 A081853

Keyword

nonn

Author

N. J. A. Sloane, Apr 13 2003

Status

approved