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A086064
In decimal representation: smallest k>1 such that n is a substring of n*k.
4
2, 10, 6, 10, 6, 3, 6, 10, 6, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 6, 10, 10, 10, 10, 5, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 6, 10, 10, 10, 10, 10, 10, 10, 10, 10, 3, 10, 10, 10, 10, 10, 10, 10, 10, 10, 6, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10
OFFSET
0,1
COMMENTS
1 < a(n) <= 10; 4, 7 and 8 do not occur.
FORMULA
a(n) = A087217(n)/n for n>0. - Reinhard Zumkeller, Aug 26 2003
PROG
(Python)
def a(n):
s = str(n)
return next(k for k in range(2, 11) if s in str(n*k))
print([a(n) for n in range(71)]) # Michael S. Branicky, Feb 23 2025
CROSSREFS
Cf. A045537.
Sequence in context: A047816 A095845 A105801 * A076374 A142954 A082225
KEYWORD
nonn,base
AUTHOR
Reinhard Zumkeller, Aug 24 2003
STATUS
approved