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 A329792 Smallest positive k such that k*n contains only the digits 1,2,3,4,5, or -1 if no such k exists. 2
 -1, 1, 1, 1, 1, 1, 2, 2, 3, 5, -1, 1, 1, 1, 1, 1, 2, 2, 3, 6, -1, 1, 1, 1, 1, 1, 2, 2, 4, 5, -1, 1, 1, 1, 1, 1, 4, 3, 3, 6, -1, 1, 1, 1, 1, 1, 7, 3, 3, 5, -1, 1, 1, 1, 1, 1, 2, 2, 4, 6, -1, 2, 2, 4, 8, 5, 2, 2, 8, 5, -1, 2, 2, 7, 3, 3, 2, 2, 3, 7, -1, 3, 16, 4, 3, 3, 4, 5, 4, 5, -1 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,7 COMMENTS a(n) > 0 iff n is not a multiple of 10. REFERENCES G. Galperin  and Y. J. Ionin (Proposers), and M. Reid (Solver), Problem 12034, Amer. Math. Monthly, 126:10, 950-951, Dec. 2019. LINKS Rémy Sigrist, Table of n, a(n) for n = 0..25000 PROG (Python) def A329792(n):     if n % 10:         m, s = 1, set('12345')         while not set(str(m*n)) <= s:             m += 1         return m     else:         return -1 # Chai Wah Wu, Dec 04 2019 CROSSREFS Cf. A084545, A329793. Sequence in context: A093927 A067088 A065519 * A058256 A140183 A280408 Adjacent sequences:  A329789 A329790 A329791 * A329793 A329794 A329795 KEYWORD sign,look,base AUTHOR N. J. A. Sloane, Dec 03 2019 STATUS approved

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Last modified January 23 10:50 EST 2020. Contains 331171 sequences. (Running on oeis4.)