The number of reversible primes (palindromic or emirps) by increasing permissible leading digit and by length.
A220344
The number of reversible primes (palindromic or emirps) by increasing permissible leading digit and by length.
Terms
- a(0) =1a(1) =1a(2) =1a(3) =1a(4) =3a(5) =2a(6) =3a(7) =1a(8) =12a(9) =9a(10) =12a(11) =10a(12) =60a(13) =51a(14) =43a(15) =50a(16) =413a(17) =377a(18) =346a(19) =363a(20) =2632a(21) =2422a(22) =2253a(23) =2231a(24) =18960a(25) =17923a(26) =17221a(27) =17038a(28) =141594a(29) =134894
External references
- oeis: A220344