A051829 Number of numbers below 10^n with nonzero multiplicative digital root 9.

1, 5, 30, 210, 1850, 19528, 233289, 2805652, 31522803, 326897695, 3190607915, 30250443755, 287335303424, 2785929699350, 27611310448037, 276727430606458

Offset: 1

Author

Dan Hoey, Dec 09 1999

Keywords

• nonn
• base
• hard

References

• William Mayne, sci.math, Jun 15 1991

Crossrefs

Cf. A051802, A051811, A051820.

Formula

# { i : 10^(n-1) < i < 10^n and A051802(i)=9 }