A051822 Number of numbers below 10^n with nonzero multiplicative digital root 2.

1, 16, 224, 2613, 27458, 271155, 2620040, 25457267, 251964768, 2537869322, 25777827199, 261509437991, 2634407279895, 26321038031960, 261379965909359, 2589357329707966

Offset: 1

Author

Dan Hoey, Dec 09 1999

Keywords

• nonn
• base
• hard

References

• William Mayne, sci.math, Jun 15 1991

Crossrefs

Cf. A051802, A051804, A051813.

Formula

# { i : 10^(n-1) < i < 10^n and A051802(i)=2 }