1,1

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

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

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

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

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

Cf. A000079, A007377, A027870, A055641.

Sequence in context: A258744 A219251 A154770 * A305130 A098395 A207968

Adjacent sequences: A320598 A320599 A320600 * A320602 A320603 A320604

nonn,base

M. F. Hasler, Oct 16 2018

approved