A081851 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).

5, 7, 36, 1711985, 13, 15, 1700, 114, 168, 42000323, 275, 324, 58, 62, 23658393, 6055, 58311963, 9321, 121770, 13760, 135, 141, 1960, 344148, 5734229, 3391007266515, 8825709, 23546737390632357, 244, 252, 1526332099115586230, 105432399233, 27538521, 5680

Offset

2,1

Links

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

Maple

g:= proc(n) local b0, b, count;
  b0:= (2*n+1)/4; b:= b0;
  for count from 1 do
    b:= b0 * ceil(b);
    if b::integer then return b fi
  od
end proc:
map(g, [$2..100]); # Robert Israel, Sep 21 2018

Crossrefs

Cf. A073524, A081849, A081850.

Sequence in context: A176958 A196203 A196473 * A342504 A192156 A322380

Adjacent sequences: A081848 A081849 A081850 * A081852 A081853 A081854

Keyword

nonn

Author

N. J. A. Sloane, Apr 13 2003

Status

approved