Number of divisors = first digit.

Terms

a(0) =1a(1) =2a(2) =23a(3) =29a(4) =46a(5) =63a(6) =68a(7) =88a(8) =211a(9) =223a(10) =227a(11) =229a(12) =233a(13) =239a(14) =241a(15) =251a(16) =257a(17) =263a(18) =269a(19) =271a(20) =277a(21) =281a(22) =283a(23) =293a(24) =361a(25) =403a(26) =407a(27) =411a(28) =413a(29) =415