A171765 a(n) = 0 if n <= 10; for n >= 11, a(n) = product of digits of n.

0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 2, 4, 6, 8, 10, 12, 14, 16, 18, 0, 3, 6, 9, 12, 15, 18, 21, 24, 27, 0, 4, 8, 12, 16, 20, 24, 28, 32, 36, 0, 5, 10, 15, 20, 25, 30, 35, 40, 45, 0, 6, 12, 18, 24, 30, 36, 42, 48, 54, 0, 7, 14, 21, 28, 35, 42, 49, 56, 63, 0, 8, 16, 24, 32, 40, 48, 56, 64, 72, 0, 9, 18, 27, 36, 45, 54, 63, 72, 81, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0

Offset: 0

Author

Felice Russo, Oct 11 2010

Keywords

• nonn
• base
• easy

Crossrefs

Cf. A007954.

Programs

Maple

A171765 := proc(n)
    if n<= 10 then
        0;
    else
        A007954(n);
    end if:
end proc: # R. J. Mathar, Jan 11 2020

Mathematica

Table[If[n<11,0,Times@@IntegerDigits[n]],{n,0,100}] (* Harvey P. Dale, Aug 02 2016 *)

PARI

a(n)=if(n<=9,0,n=digits(n); prod(i=1,#n,n[i])) \\ Charles R Greathouse IV, Aug 25 2014