A320601 Exponents of powers of two having a digit zero in decimal.

10, 11, 12, 17, 20, 21, 22, 23, 26, 29, 30, 38, 40, 41, 42, 43, 44, 45, 46, 47, 48, 50, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 68, 69, 70, 71, 73, 74, 75, 78, 79, 80, 82, 83, 84, 85, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100, 101, 102, 103, 104, 105

Offset

1,1

Comments

Complement of A007377. It is a long-standing open problem to show that this sequence contains all numbers > 86.

Links

Table of n, a(n) for n=1..70.

Formula

{ n | A027870(n) > 0}, where A027870 = A055641 o A000079.

Example

The first term is a(1) = 10 since 2^10 = 1024 is the smallest power of 2 having a digit 0.

Prog

(PARI) for(n=1, 199, vecmin(digits(2^n))||print1(n", "))

Crossrefs

Cf. A000079, A007377, A027870, A055641.

Sequence in context: A258744 A219251 A154770 * A305130 A098395 A207968

Adjacent sequences: A320598 A320599 A320600 * A320602 A320603 A320604

Keyword

nonn,base

Author

M. F. Hasler, Oct 16 2018

Status

approved