a(n) is the number of nonnegative numbers < 10^n with all digits distinct.

Terms

a(0) =1a(1) =10a(2) =91a(3) =739a(4) =5275a(5) =32491a(6) =168571a(7) =712891a(8) =2345851a(9) =5611771a(10) =8877691a(11) =8877691a(12) =8877691a(13) =8877691a(14) =8877691a(15) =8877691a(16) =8877691a(17) =8877691a(18) =8877691a(19) =8877691a(20) =8877691a(21) =8877691a(22) =8877691a(23) =8877691a(24) =8877691a(25) =8877691a(26) =8877691a(27) =8877691a(28) =8877691a(29) =8877691