A371918 The smallest unused positive number such that 2^a(n) contains n as a substring.

10, 4, 1, 5, 2, 8, 6, 15, 3, 12, 17, 40, 7, 27, 18, 21, 14, 34, 30, 13, 11, 24, 43, 41, 19, 50, 28, 38, 47, 32, 22, 49, 25, 63, 33, 35, 16, 37, 23, 42, 53, 44, 59, 45, 46, 52, 60, 31, 20, 39, 54, 9, 51, 29, 74, 57, 48, 56, 61, 69, 55, 58, 66, 76, 26, 73, 72, 36, 62, 82, 64, 70, 77, 67, 65, 91, 78

Offset: 0

Author

Scott R. Shannon, Apr 12 2024

Keywords

• nonn
• base

Comments

The sequence is conjectured to be a permutation of the positive integers.

Examples

			a(0) = 10 as 2^10 = 1024 which contains '0' as a substring.
a(6) = 6 as 2^6 = 64 which contains '6' as a substring. Note that 2^4 also contains '6' but 4 has already been used. This is the first term to differ from A063565.
		

Links

• Scott R. Shannon, Table of n, a(n) for n = 0..10000

Crossrefs

Cf. A000079, A371904, A063565, A368866.