a(n) is the number of n-digit positive integers with exactly four distinct base 10 digits.

A337314

a(n) is the number of n-digit positive integers with exactly four distinct base 10 digits.

Terms

    a(0) =0a(1) =0a(2) =0a(3) =4536a(4) =45360a(5) =294840a(6) =1587600a(7) =7715736a(8) =35244720a(9) =154700280a(10) =661122000a(11) =2773768536a(12) =11487556080a(13) =47136955320a(14) =192126589200a(15) =779279814936

External references