A196244 Number of distinct values taken by r^r^...^r where r=1/2 (with n r's and parentheses inserted in all possible ways).

1, 1, 2, 4, 9, 20, 47, 111, 271, 670, 1685, 4295, 11074, 28824

Offset

1,3

Links

Table of n, a(n) for n=1..14.

Mathematica

f[1] = {1/2}; f[n_] := f[n] = Union[Flatten[Table[Outer[Power, f[k], f[n - k]], {k, n - 1}]], SameTest -> Equal]; Table[Length[f[n]], {n, 1, 10}] (* Vladimir Reshetnikov, Nov 01 2011 *)

Crossrefs

Cf. A002845, A082499.

Sequence in context: A036618 A349014 A003018 * A035084 A363557 A213905

Adjacent sequences: A196241 A196242 A196243 * A196245 A196246 A196247

Keyword

nonn,more

Author

Vladimir Reshetnikov, Oct 27 2011

Extensions

a(13)-a(14) from Alois P. Heinz, Feb 20 2013

Status

approved