A151783 a(n) = 4^(wt(n) - 1) where wt(n) = A000120(n).

1, 1, 4, 1, 4, 4, 16, 1, 4, 4, 16, 4, 16, 16, 64, 1, 4, 4, 16, 4, 16, 16, 64, 4, 16, 16, 64, 16, 64, 64, 256, 1, 4, 4, 16, 4, 16, 16, 64, 4, 16, 16, 64, 16, 64, 64, 256, 4, 16, 16, 64, 16, 64, 64, 256, 16, 64, 64, 256, 64, 256, 256, 1024, 1, 4, 4, 16, 4, 16, 16, 64, 4, 16, 16, 64, 16, 64

Offset

1,3

Links

Table of n, a(n) for n=1..77.

Example

From Omar E. Pol, Jul 21 2009: (Start)
If written as a triangle:
  1;
  1,4;
  1,4,4,16;
  1,4,4,16,4,16,16,64;
  1,4,4,16,4,16,16,64,4,16,16,64,16,64,64,256;
  1,4,4,16,4,16,16,64,4,16,16,64,16,64,64,256,4,16,16,64,16,64,64,256,16,64,...
(End)

Prog

(Python 3.10+)
def A151783(n): return 1<<(n.bit_count()-1<<1) # Chai Wah Wu, Nov 15 2022

Crossrefs

Cf. A000120, A048881, A048896, A147610, A151780.

Cf. A000302, A102376. [Omar E. Pol, Jul 21 2009]

A102376 is a very similar sequence.

Sequence in context: A350639 A347264 A328147 * A258853 A275791 A093561

Adjacent sequences: A151780 A151781 A151782 * A151784 A151785 A151786

Keyword

nonn

Author

N. J. A. Sloane, Jun 25 2009

Status

approved