
COMMENTS

There are total 224 numbers and 224246090, 632258960, 824791960, 851750490, and 904719030 are the only 9digit numbers to satisfy the requirement.


EXAMPLE

There are five onedigit numbers divisible by the first prime so a(1)=5.
For twodigit 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.
