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A140451 a(1) = 1. a(n) = the smallest positive multiple of a(n-1) with exactly n 1's in its binary representation. 0
1, 3, 21, 105, 4305, 21525, 5316675, 3291021825, 38046409656325181475 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Each term is odd.

Can it be proved that there always is a positive multiple of each a(n-1) that has exactly n binary 1's? Or is the {a(k)} sequence finite?

a(10) <= 1 + 2^100 + 2^236 + 2^238 + 2^341 + 2^542 + 2^566 + 2^568 + 2^674 + 2^723. [From Max Alekseyev, Oct 12 2008]

LINKS

Table of n, a(n) for n=1..9.

CROSSREFS

Sequence in context: A134057 A128281 A034268 * A054147 A233582 A043012

Adjacent sequences:  A140448 A140449 A140450 * A140452 A140453 A140454

KEYWORD

base,more,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

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Last modified January 24 04:31 EST 2018. Contains 298115 sequences.