A174995 Products of decimal digits.

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

Offset: 1

Author

Reinhard Zumkeller, Apr 03 2010, Apr 05 2010

Keywords

• base
• fini
• full
• nonn

Comments

Apart from the initial zero: finite subset of A002473 with 37 elements: a(37)=81=9*9;

a(n) = A079904(j,i) for certain i,j with 0<=i<=j<=9.

Programs

Mathematica

Union[Times@@@Tuples[Range[0,9],2]] (* Harvey P. Dale, Oct 08 2011 *)