A073909 Smallest number m such that m and the product of digits of m are both divisible by 2n, or 0 if no such number exists.

2, 4, 6, 8, 0, 168, 378, 48, 36, 0, 0, 168, 0, 476, 0, 288, 0, 1296, 0, 0, 378, 0, 0, 384, 0, 0, 1296, 728, 0, 0, 0, 448, 0, 0, 0, 1368, 0, 0, 0, 0, 0, 672, 0, 0, 0, 0, 0, 384, 7742, 0, 0, 0, 0, 1296, 0, 784, 0, 0, 0, 0, 0, 0, 3276, 2688, 0, 0, 0, 0, 0, 0, 0, 3168, 0, 0, 0, 0, 0, 0, 0

Offset

1,1

Comments

Here 0 is regarded as not divisible by any number.

a(n) = 0 if n is divisible by 5 or contains a prime divisor > 9. - Sascha Kurz, Aug 23 2002

Links

Table of n, a(n) for n=1..79.

Formula

a(n) = A085124(2*n). - R. J. Mathar, Jun 21 2018

Maple

f := 2:for i from 1 to 400 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..400);

Crossrefs

Cf. A073906, A085124, A073908, A073910, A073911, A073912.

Sequence in context: A004520 A169918 A169916 * A036211 A127353 A032763

Adjacent sequences: A073906 A073907 A073908 * A073910 A073911 A073912

Keyword

nonn,base

Author

Amarnath Murthy, Aug 18 2002

Extensions

More terms from Sascha Kurz, Aug 23 2002

Status

approved