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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
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
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
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Apr 13 2003
STATUS
approved