A244958 Smallest positive multiple of n whose base-7 representation contains only 0's and 1's.
1, 8, 57, 8, 50, 19608, 7, 8, 351, 50, 2409, 19608, 351, 56, 2745, 400, 16864, 134856, 57, 400, 399, 2794, 17158, 19608, 50, 19552, 351, 56, 137257, 120450, 16864, 2752, 2409, 16864, 350, 134856, 117993, 19608, 351, 400, 134849, 137256, 344, 16808, 2745
Offset: 1
Links
- Harvey P. Dale, Table of n, a(n) for n = 1..1000
- Ed Pegg Jr., 'Binary' Puzzle
- Eric M. Schmidt, Sage code to compute this sequence (use b=7)
- Chai Wah Wu, Pigeonholes and repunits, Amer. Math. Monthly, 121 (2014), 529-533.
Programs
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Mathematica
With[{cl=Rest[{FromDigits[#,7],FromDigits[#]}&/@Tuples[{0,1},7]]},Table[SelectFirst[cl,Mod[ #[[1]],n]==0&],{n,50}]][[;;,1]] (* Harvey P. Dale, Feb 01 2024 *)
Extensions
Data corrected, Offset corrected, Mathematica program corrected and replaced, and b-file replaced by Harvey P. Dale, Feb 01 2024