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A085124
Smallest multiple of n whose digital product is also a multiple of n, or 0 if no such number exists.
9
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
1,2
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.
Sequence in context: A297232 A093691 A004176 * A252648 A054054 A115353
KEYWORD
base,nonn
AUTHOR
Amarnath Murthy, Jul 06 2003
EXTENSIONS
More terms from David Wasserman, Jan 27 2005
Comments edited by Jon E. Schoenfield, Mar 30 2014
STATUS
approved