This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A244927 #19 Mar 05 2025 01:55:11 %S A244927 1,5,37,25,2,185,15873,125,12345679,1,1,925,8547,79365,74,625, %T A244927 65359477124183,61728395,5847953216374269,5,5291,5, %U A244927 48309178743961352657,4625,4,42735,4115226337448559670781893,396825,38314176245210727969348659,37,3584229390681,3125,3367,326797385620915 %N A244927 Least positive number k such that k*n written in base 10 is either a repunit or of the form 1111....0000. %H A244927 M. F. Hasler, <a href="/A244927/b244927.txt">Table of n, a(n) for n = 1..1016</a> (first 100 terms from Chai Wah Wu), Mar 04 2025 %F A244927 a(n) = A244859(n)/n. %F A244927 a(3^k) = (10^(3^k)-1)/3^(k+2). a(n) <= (10^n-1)/(9*n). If n > 2 is not a power of 3, then a(n) <= (10^(n-1)-1)/(9*n). - _Chai Wah Wu_, Mar 04 2025 %e A244927 For n = 7, 15873*7 = 111111 and this is the least positive multiple of 7 that is either a repunit or of the form 1111...000. %Y A244927 Cf. A244859, A079339, A004290. Equal to A079339 for the first 6 terms. %K A244927 nonn,base %O A244927 1,2 %A A244927 _Chai Wah Wu_, Jul 08 2014