Number of distinct primes which occur as subsequences of the sequence of digits of n.

Terms

a(0) =0a(1) =1a(2) =1a(3) =0a(4) =1a(5) =0a(6) =1a(7) =0a(8) =0a(9) =0a(10) =1a(11) =1a(12) =2a(13) =0a(14) =1a(15) =0a(16) =2a(17) =0a(18) =1a(19) =1a(20) =1a(21) =1a(22) =3a(23) =1a(24) =2a(25) =1a(26) =2a(27) =1a(28) =2a(29) =1