cp's OEIS Frontend

A073910 Smallest number m such that m and the product of digits of m are both divisible by 3n, or 0 if no such number exists.

%I A073910 #19 Jan 26 2020 16:58:48
%S A073910 3,6,9,168,135,36,273,168,999,0,0,1296,0,378,495,384,0,1296,0,0,1197,
%T A073910 0,0,1368,3525,0,2997,672,0,0,0,384,0,0,735,1296,0,0,0,0,0,3276,0,0,
%U A073910 3915,0,0,3168,7497,0,0,0,0,5994,0,7896,0,0,0,0,0,0,7938,2688,0,0,0,0,0,0,0
%N A073910 Smallest number m such that m and the product of digits of m are both divisible by 3n, or 0 if no such number exists.
%C A073910 Here 0 is regarded as not divisible by any number.
%C A073910 a(n) = 0 if 10 divides 3n or n contains a prime divisor > 9. - _Sascha Kurz_, Aug 23 2002
%H A073910 Robert Israel, <a href="/A073910/b073910.txt">Table of n, a(n) for n = 1..10000</a>
%F A073910 a(n) = A085124(3*n). - _R. J. Mathar_, Jun 21 2018
%p A073910 f := 3:for i from 1 to 1000 do b := ifactors(f*i)[2]: if b[nops(b)][1]>9 or (f*i mod 10) =0 then a[i] := 0:else j := 0:while true do j := j+f*i:c := convert(j,base,10):d := product(c[k],k=1..nops(c)): if (d mod f*i)=0 and d>0 then a[i] := j:break:fi:od:fi:od:seq(a[k],k=1..1000);
%Y A073910 Cf. A073906, A073908, A073909, A073911, A073912, A085124.
%K A073910 nonn,base
%O A073910 1,1
%A A073910 _Amarnath Murthy_, Aug 18 2002
%E A073910 More terms from _Sascha Kurz_, Aug 23 2002