A074162 a(1) = 1; a(n) = smallest multiple of n (>n) using all nonprime digits (1,4,6,8,9 and 0) if n is a prime else using all prime digits and 1 if n is composite; or 0 if no such number exists.

1, 4, 6, 12, 10, 12, 14, 32, 27, 0, 44, 72, 91, 112, 75, 32, 68, 72, 114, 0, 231, 132, 46, 72, 75, 52, 135, 112, 116, 0, 186, 352, 132, 272, 175, 72, 111, 152, 117, 0, 164, 252, 86, 132, 135, 322, 94, 1152, 735, 0, 153, 312, 106, 1512, 275, 112, 171, 232, 118, 0, 488

Offset: 1

Author

Amarnath Murthy, Aug 29 2002

Keywords

• base
• nonn

Comments

a(10k) = 0. Are there other values of n such that a(n) =0?

A pigeonhole argument shows the conjecture to be true (that only a(10k) = 0). - Joshua Zucker, May 08 2006

Conjecture (contradicts Zucker statement): a(k*5^6) = 0. - Sean A. Irvine, Jan 13 2025

Extensions

Corrected and extended by Joshua Zucker, May 08 2006