The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 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

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified August 12 09:11 EDT 2024. Contains 375085 sequences. (Running on oeis4.)