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A032540 Numbers that, when expressed in base 4 and then interpreted in base 10, yield a multiple of the original number. 4
0, 1, 2, 3, 6, 24, 120, 171, 177, 273, 362, 440, 546, 819, 1418, 1560, 1582, 1638, 1760, 1806, 2400, 2841, 2927, 3640, 4706, 4882, 5720, 6328, 6552, 7040, 7224, 9431, 9600, 10101, 14560, 20202, 22880, 24800, 25080, 25312, 28896, 32760, 36974, 38400 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,3
COMMENTS
n such that A007090(n) is a multiple of n. - Robert Israel, Sep 13 2018
LINKS
Giovanni Resta, Table of n, a(n) for n = 1..153 (terms < 5*10^12, first 100 terms from Robert Israel)
EXAMPLE
24 in base 4 is 120, which interpreted in base 10 is 120 = 5*24.
MAPLE
filter:= proc(n) local L, t;
L:= convert(n, base, 4);
t:= add(L[i]*10^(i-1), i=1..nops(L));
t mod n = 0
end proc:
filter(0):=true:
select(filter, [$0..10^5]); # Robert Israel, Sep 13 2018
MATHEMATICA
Join[{0}, Select[Range[40000], Divisible[FromDigits[IntegerDigits[#, 4]], #]&]] (* Harvey P. Dale, Apr 20 2011 *)
CROSSREFS
Sequence in context: A027163 A160683 A099000 * A063728 A333420 A296259
KEYWORD
base,nonn
AUTHOR
Patrick De Geest, Apr 15 1998
EXTENSIONS
More terms from Erich Friedman and Naohiro Nomoto, Aug 06 2001
Offset changed by Robert Israel, Sep 13 2018
Name edited by Jon E. Schoenfield, Oct 25 2019
STATUS
approved

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Last modified April 19 19:02 EDT 2024. Contains 371798 sequences. (Running on oeis4.)