Number of primes less than 10^n with digits in nondecreasing order.

Terms

a(0) =0a(1) =4a(2) =16a(3) =50a(4) =132a(5) =315a(6) =689a(7) =1413a(8) =2636a(9) =4967a(10) =8563a(11) =14481a(12) =23593a(13) =37127a(14) =56809a(15) =86779a(16) =127096a(17) =184517a(18) =264288a(19) =368794a(20) =510442a(21) =707483a(22) =948307a(23) =1268871a(24) =1689642a(25) =2204795a(26) =2866855a(27) =3729223a(28) =4738019a(29) =6013021