A032543 Numbers that, when expressed in base 5 and then interpreted in base 10, yield a multiple of the original number.

0, 1, 2, 3, 4, 5, 10, 15, 20, 25, 50, 75, 100, 125, 160, 224, 237, 250, 320, 330, 375, 490, 500, 625, 800, 1000, 1120, 1185, 1250, 1600, 1650, 1875, 2450, 2500, 3125, 3800, 4000, 4704, 5000, 5600, 5925, 6250, 7600, 8000, 8250, 9375, 10000, 12250

Offset

1,3

Comments

From Robert Israel, Apr 10 2016: (Start)

n for which n divides A007091(n).

If n is in the sequence, then so is 5*n. (End)

Links

Giovanni Resta, Table of n, a(n) for n = 1..577 (terms < 5*10^12, first 147 terms from Robert Israel)

Example

25 in base 5 is 100, which interpreted in base 10 is 100 = 4 * 25.
224 in base 5 is 1344, which interpreted in base 10 is 1344 = 6 * 224.

Maple

filter:= proc(n) local L, i;
L:= convert(n, base, 5);
add(L[i]*10^(i-1), i=1..nops(L)) mod n = 0
end proc:
0, op(select(filter, [$1..10^5])); # Robert Israel, Apr 10 2016

Mathematica

Select[Range[0, 13000], Divisible[FromDigits[IntegerDigits[#, 5]], #] &] (* Harvey P. Dale, Feb 01 2011 *)

Crossrefs

Cf. A007091, A032542, A032544.

Sequence in context: A364902 A032940 A064419 * A140730 A273732 A282032

Adjacent sequences: A032540 A032541 A032542 * A032544 A032545 A032546

Keyword

nonn,base

Author

Patrick De Geest, Apr 15 1998

Extensions

Example and better description from Erich Friedman, Jul 21 2001

Edited by Erich Friedman, Feb 09 2002

Offset changed and 0 inserted by Robert Israel, Apr 11 2016

Name edited by Jon E. Schoenfield, Oct 25 2019

Status

approved