A140451 a(1) = 1. a(n) = the smallest positive multiple of a(n-1) with exactly n 1's in its binary representation.

1, 3, 21, 105, 4305, 21525, 5316675, 3291021825, 38046409656325181475

Offset

1,2

Comments

Each term is odd.

a(10) = 2^617 + 2^529 + 2^527 + 2^401 + 2^352 + 2^284 + 2^240 + 2^239 + 2^154 + 1 has 186 decimal digits. - Max Alekseyev, Feb 04 2018

The sequence is infinite. - Max Alekseyev, Feb 04 2018

Links

Max Alekseyev, Table of n, a(n) for n = 1..10

Crossrefs

Sequence in context: A134057 A128281 A034268 * A054147 A233582 A043012

Adjacent sequences: A140448 A140449 A140450 * A140452 A140453 A140454

Keyword

base,nonn

Author

Leroy Quet, Jul 21 2008

Extensions

First 8 terms calculated by R. J. Mathar and Jack Brennen.

a(9) from Max Alekseyev, Jul 22 2008

Status

approved