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%I #7 Sep 24 2018 15:53:32
%S 5,7,36,1711985,13,15,1700,114,168,42000323,275,324,58,62,23658393,
%T 6055,58311963,9321,121770,13760,135,141,1960,344148,5734229,
%U 3391007266515,8825709,23546737390632357,244,252,1526332099115586230,105432399233,27538521,5680
%N Consider recurrence b(0) = (2n+1)/4, b(n) = b(0)*ceiling(b(n-1)); sequence gives first integer reached (or -1 if no integer is ever reached).
%H Robert Israel, <a href="/A081851/b081851.txt">Table of n, a(n) for n = 2..10000</a>
%p g:= proc(n) local b0, b, count;
%p b0:= (2*n+1)/4; b:= b0;
%p for count from 1 do
%p b:= b0 * ceil(b);
%p if b::integer then return b fi
%p od
%p end proc:
%p map(g, [$2..100]); # _Robert Israel_, Sep 21 2018
%Y Cf. A073524, A081849, A081850.
%K nonn
%O 2,1
%A _N. J. A. Sloane_, Apr 13 2003