login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A051815 Number of n-digit numbers with nonzero multiplicative digital root 4. 1
1, 12, 105, 780, 5452, 39979, 336081, 3263355, 34518027, 372779338, 3957184040, 40729856248, 406862880846, 3979167973684, 38556471560342, 374259579575061 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
REFERENCES
William Mayne, sci.math, Jun 15 1991
LINKS
FORMULA
# { i : 10^(n-1) < i < 10^n and A051802(i)=4 }
CROSSREFS
Sequence in context: A353549 A094530 A157024 * A004321 A016223 A027142
KEYWORD
nonn,base,hard
AUTHOR
Dan Hoey, Dec 09 1999
STATUS
approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified July 13 21:17 EDT 2024. Contains 374288 sequences. (Running on oeis4.)