A259085 a(n) = largest k such that the decimal representation of prime(n)^k does not contain the digit 1, or -1 if no such k exists.

91, 43, 42, 30, -1, 14, 13, 23, 7, 3, -1, 6, -1, 3, 5, 2, 19, -1, 9, -1, 17, 5, 6, 9, 6, -1, -1, -1, 11, -1, 13, -1, 7, -1, 5, -1, 5, 3, 13, 6, 7, -1, -1, 7, 10, 15, -1, 2, 5, 7, 2, 9, -1, -1, 2, 6, 1, -1, 2, -1, 21, 2, 3, -1, 3, 11, -1, 5, 11, 3, 3, 3, 5, 1

Offset: 1

Author

N. J. A. Sloane, Jun 18 2015

Keywords

• sign
• base

Comments

These values are only conjectural.

Links

• Hiroaki Yamanouchi, Table of n, a(n) for n = 1..500
• Popular Computing (Calabasas, CA), Two Tables, Vol. 1, (No. 9, Dec 1973), page PC9-16.

Crossrefs

Cf. A094776, A259081-A259086.

Extensions

a(14)-a(74) from Hiroaki Yamanouchi, Jun 19 2015