Smallest prime obtained by sandwiching n between a number with identical digits, or 0 if no such prime exists. Primes of the form k n k where all the digits of k are identical.
A090287
Smallest prime obtained by sandwiching n between a number with identical digits, or 0 if no such prime exists. Primes of the form k n k where all the digits of k are identical.
Terms
- a(0) =101a(1) =313a(2) =727a(3) =131a(4) =11411a(5) =151a(6) =777767777a(7) =373a(8) =181a(9) =191a(10) =9109a(11) =0a(12) =7127a(13) =331333a(14) =991499a(15) =1151a(16) =3163a(17) =1171a(18) =1181a(19) =9199a(20) =1201a(21) =112111a(22) =0a(23) =1231a(24) =7247a(25) =3253a(27) =1111271111a(28) =11128111a(29) =1291a(30) =1301
External references
- oeis: A090287