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A343810
Numbers that contain only the digits 0,4,8. Permutable multiples of 4: numbers k such that every permutation of the digits of k is a multiple of 4.
1
0, 4, 8, 40, 44, 48, 80, 84, 88, 400, 404, 408, 440, 444, 448, 480, 484, 488, 800, 804, 808, 840, 844, 848, 880, 884, 888, 4000, 4004, 4008, 4040, 4044, 4048, 4080, 4084, 4088, 4400, 4404, 4408, 4440, 4444, 4448, 4480, 4484, 4488, 4800, 4804
OFFSET
0,2
COMMENTS
Also permutable multiples of 4: numbers k such that every permutation of the digits of k is a multiple of 4.
FORMULA
a(n) = 4*A007089(n).
EXAMPLE
480 = 4*120, 408 = 4*102, 840 = 4*210, 804 = 4*201, 048 = 4*12, 084 = 4*21.
MAPLE
f:= proc(n) local L, i;
L:= convert(n, base, 3);
4*add(L[i]*10^(i-1), i=1..nops(L))
end proc:
map(f, [$0..100]); # Robert Israel, Apr 30 2021
MATHEMATICA
FromDigits /@ Tuples[{0, 4, 8}, 4] (* Amiram Eldar, Apr 30 2021 *)
PROG
(PARI) a(n) = fromdigits(digits(n, 3))*4 \\ Rémy Sigrist, May 05 2021
KEYWORD
nonn,base,easy
AUTHOR
Ctibor O. Zizka, Apr 30 2021
STATUS
approved