A061934 Numbers n such that n divides the (right) concatenation of all numbers <= n written in base 5 (most significant digit on right, least significant zeros not written).
1, 16, 19, 207, 350376, 723792, 853456, 1894016
Offset: 1
Examples
See A061931 for example.
Crossrefs
Programs
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Mathematica
cat = 0; k = 1; lst = {}; While[k < 100000, c = FromDigits@ Reverse@ IntegerDigits[k, 5]; cat = cat*10^Floor[ Log10[c] + 1] + c; If[ Mod[ FromDigits[ IntegerDigits@ cat, 5], k] == 0, AppendTo[lst, k]; Print[k]]; k++]; lst (* Robert G. Wilson v, Oct 17 2011 *) b = 5; c = {}; Select[Range[10^4], Divisible[FromDigits[ c = Join[c, IntegerDigits[IntegerReverse[#, b], b]], b], #] &] (* Robert Price, Mar 07 2020 *) -
PARI
lista(nn, m=5) = my(s, t); for(k=1, nn, s=k/m^valuation(k, m); while(s, t=t*m+s%m; s\=m); if(t%k==0, print1(k, ", "))); \\ Jinyuan Wang, Dec 05 2020
Extensions
Edited and updated by Larry Reeves (larryr(AT)acm.org), Apr 12 2002
a(6)-a(8) from Lars Blomberg, Oct 17 2011
Comments