A051814 Number of n-digit numbers with nonzero multiplicative digital root 3.

1, 7, 40, 240, 1448, 8630, 53545, 371845, 3267453, 36428242, 442762543, 5217693527, 57321559329, 586532407659, 5666269188709, 52728701479194

Offset: 1

Author

Dan Hoey, Dec 09 1999

Keywords

• nonn
• base
• hard

References

• William Mayne, sci.math, Jun 15 1991

Crossrefs

Cf. A051802, A051805, A051823.

Formula

# { i : 10^(n-1) < i < 10^n and A051802(i)=3 }