Number of n-digit base-3 deletable primes.

Terms

a(0) =1a(1) =2a(2) =4a(3) =7a(4) =13a(5) =24a(6) =38a(7) =72a(8) =122a(9) =226a(10) =400a(11) =684a(12) =1246a(13) =2381a(14) =4384a(15) =8330a(16) =15839a(17) =30617a(18) =58764a(19) =113987a(20) =221994a(21) =434498a(22) =852036a(23) =1673320a(24) =3296641a(25) =6509179