cp's OEIS Frontend

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).

%I A081850 #8 Sep 22 2018 04:14:30
%S A081850 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,
%T A081850 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,
%U A081850 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
%N 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).
%H A081850 Robert Israel, <a href="/A081850/b081850.txt">Table of n, a(n) for n = 2..10000</a>
%p A081850 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;
%Y A081850 Cf. A073524, A081849, A081851.
%K A081850 nonn
%O A081850 2,1
%A A081850 _N. J. A. Sloane_, Apr 13 2003