A161324 Let b(m,k) be the k-th binary digit (starting at k=1, reading right to left) in the base-2 representation of m. (So: n = Sum_{k>=0} b(k+1)*2^k.) A positive integer m is included in this sequence if and only if m = Product_{k>=1} k^b(m,k).

1, 2, 6, 12, 576000

Offset

1,2

Comments

Hans Havermann found term a(5).

Jack Brennen says that there are no other terms < 2^32.

a(6) > 2^80 if it exists. - Bert Dobbelaere, Apr 19 2019

Links

Table of n, a(n) for n=1..5.

Example

12 = 1100_2. And 12 = 4^1 * 3^1 * 2^0 * 1^0. So 12 is in the sequence.

Crossrefs

Sequence in context: A089415 A282974 A181063 * A226603 A116534 A130533

Adjacent sequences: A161321 A161322 A161323 * A161325 A161326 A161327

Keyword

base,more,nonn

Author

Leroy Quet, Jun 07 2009

Status

approved