A085124 Smallest multiple of n whose digital product is also a multiple of n, or 0 if no such number exists.

1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 0, 168, 0, 378, 135, 48, 0, 36, 0, 0, 273, 0, 0, 168, 525, 0, 999, 476, 0, 0, 0, 288, 0, 0, 175, 1296, 0, 0, 0, 0, 0, 378, 0, 0, 495, 0, 0, 384, 3577, 0, 0, 0, 0, 1296, 0, 728, 0, 0, 0, 0, 0, 0, 1197, 448, 0, 0, 0, 0, 0, 0, 0, 1368, 0, 0, 3525, 0, 0, 0, 0, 0

Offset: 1

Author

Amarnath Murthy, Jul 06 2003

Keywords

• base
• nonn

Comments

a(n) = 0 if n is not a term of A002473 (i.e., not a 7-smooth number).

a(n) = 0 if n is a multiple of 10.

Conjecture: otherwise, a(n) is positive.

Sequence may be redefined to avoid large number of zeros by restricting it to members of A002473 which are not divisible by 10.

Crossrefs

Cf. A002473.

Extensions

More terms from David Wasserman, Jan 27 2005

Comments edited by Jon E. Schoenfield, Mar 30 2014