(cache)A381259

A381259

Numbers obtained by concatenating powers of 2, sorted into increasing order.

1, 2, 4, 8, 11, 12, 14, 16, 18, 21, 22, 24, 28, 32, 41, 42, 44, 48, 64, 81, 82, 84, 88, 111, 112, 114, 116, 118, 121, 122, 124, 128, 132, 141, 142, 144, 148, 161, 162, 164, 168, 181, 182, 184, 188, 211, 212, 214, 216, 218, 221, 222, 224, 228, 232, 241, 242, 244, 248, 256, 264

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OFFSET

1,2

COMMENTS

Take the list {2^i: i >= 0} and concatenate its terms (allowing multiple copies) in any order; then sort the result into increasing order.

The term a(32) = 128 is a power of 2 as well as the concatenation of several powers of 2. - Rémy Sigrist, Feb 20 2025

LINKS

Rémy Sigrist, Table of n, a(n) for n = 1..11921

Rémy Sigrist, PARI program

EXAMPLE

11 is a term because it is the concatenation of 1 = 2^0 with itself;

12 is a term because it is the concatenation of 1 = 2^0 with 2 = 2^1;