A051824 Number of numbers below 10^n with nonzero multiplicative digital root 4.
1, 13, 118, 898, 6350, 46329, 382410, 3645765, 38163792, 410943130, 4368127170, 45097983418, 451960864264, 4431128837948, 42987600398290, 417247179973351
Offset: 1
References
- William Mayne, sci.math, Jun 15 1991
Formula
# { i : 10^(n-1) < i < 10^n and A051802(i)=4 }