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A220480
The number of n-digit numbers where last k digits are divisible by the k-th prime for k = 1..n.
0
5, 15, 36, 52, 48, 34, 18, 11, 5
OFFSET
1,1
COMMENTS
There are total 224 numbers and 224246090, 632258960, 824791960, 851750490, and 904719030 are the only 9-digit numbers to satisfy the requirement.
EXAMPLE
There are five one-digit numbers divisible by the first prime so a(1)=5.
For two-digit numbers, the second digit must make it divisible by 3 which gives 15 numbers: 12, 18, 24, 30, 36, 42, 48, 54, 60, 66, 72, 78, 84, 90, 96 to satisfy the requirement. So a(2)=15.
CROSSREFS
Cf. A079212.
Sequence in context: A346890 A333932 A065780 * A105720 A174655 A184631
KEYWORD
nonn,base,fini,full
AUTHOR
Shyam Sunder Gupta, Aug 07 2013
STATUS
approved