A230874 a(1)=1; thereafter a(n) = 2^a(ceiling(n/2)).

1, 2, 4, 4, 16, 16, 16, 16, 65536, 65536, 65536, 65536, 65536, 65536, 65536, 65536

Offset: 1

Author

N. J. A. Sloane, Nov 07 2013

Keywords

• nonn

Comments

a(17) through a(32) are 2^65536,

a(33) through a(64) are 2^2^65536, etc.

Crossrefs

Cf. A230863, A230875.

Formula

For n>1, a(n) = a tower of 2's of height ceiling(log_2(n)). E.g. a(15) = 2^2^2^2.