A051825 Number of numbers below 10^n with nonzero multiplicative digital root 5.

1, 8, 66, 488, 3360, 23132, 165550, 1262132, 10302943, 88755142, 788594730, 7086051536, 63890207069, 581627969769, 5421588729745, 52259542704256

Offset: 1

Author

Dan Hoey, Dec 09 1999

Keywords

• nonn
• base
• hard

References

• William Mayne, sci.math, Jun 15 1991

Crossrefs

Cf. A051802, A051807, A051816.

Formula

# { i : 10^(n-1) < i < 10^n and A051802(i)=5 }