1,3

Conjecture: consists of 0,5,6, and the numbers 11...1.

Table of n, a(n) for n=1..9.

isA328544 := proc(n)

local dgs , d, ndgs, nddgs;

ndgs := convert(n, base, 10) ;

dgs := convert(ndgs, set) ;

for d in dgs do

nddgs := convert(n*d, base, 10) ;

if not verify(ndgs, nddgs, 'sublist') then

return false;

end if;

end do:

true ;

end proc:

for n from 0 do

if isA328544(n) then

print(n) ;

end do: # R. J. Mathar, Oct 21 2019

Suggested by A328095 (which is a much more interesting sequence).

Sequence in context: A332523 A041227 A042183 * A041939 A177714 A273158

Adjacent sequences: A328541 A328542 A328543 * A328545 A328546 A328547

nonn,base

N. J. A. Sloane, Oct 19 2019

approved