A242349 Largest power of 2 <= n^2.

1, 4, 8, 16, 16, 32, 32, 64, 64, 64, 64, 128, 128, 128, 128, 256, 256, 256, 256, 256, 256, 256, 512, 512, 512, 512, 512, 512, 512, 512, 512, 1024, 1024, 1024, 1024, 1024, 1024, 1024, 1024, 1024, 1024, 1024, 1024, 1024, 1024, 2048, 2048, 2048, 2048, 2048, 2048

Offset

1,2

Comments

The first values of n that produce powers of 4 are precisely the powers of 2.

Links

Table of n, a(n) for n=1..51.

Example

a(3) = 8 because 3^2 = 9 and the largest power of 2 <= 9 is 8.

Prog

(PARI) a(n)=2^(#binary(n^2)-1) \\ Charles R Greathouse IV, May 11 2014

Crossrefs

Sequence in context: A312764 A166634 A189007 * A309521 A072603 A123535

Adjacent sequences: A242346 A242347 A242348 * A242350 A242351 A242352

Keyword

nonn,easy

Author

J. Lowell, May 11 2014

Status

approved