A272652 a(n) is the smallest even number which has n inverse images under the map x -> x + (binary weight of x).

0, 14, 134, 4102, 87112285931760246646623899502532662132742, 1852673427797059126777135760139006525652319754650249024631321344126610074239106

Offset

1,2

Comments

If the word "even" is omitted the sequence is A230303.

The next term is a(7) = 2^4233 + 130.

Links

Table of n, a(n) for n=1..6.

Example

The smallest number with two inverses is 14: the inverses are 11 = 1011_2 which maps to 11+3 = 14, and 12 = 1100_2 which maps to 12+2 = 14.

Crossrefs

Cf. A230303, A000120, A092391, A228085.

Sequence in context: A233467 A164598 A073554 * A016801 A323857 A244651

Adjacent sequences: A272649 A272650 A272651 * A272653 A272654 A272655

Keyword

nonn

Author

Max Alekseyev and N. J. A. Sloane, May 13 2016

Status

approved