A099630 Smallest and largest primes pairwise displayed with k digits from k=2,3,... with repeated decimal digits.

11, 11, 101, 997, 1009, 9973, 10007, 99991, 100003, 999983, 1000003, 9999991, 10000019, 99999989, 100000007, 999999937, 1000000007, 9999999967, 10000000019, 99999999977, 100000000003, 999999999989, 1000000000039, 9999999999971, 10000000000037, 99999999999973

Offset: 1

Author

Labos Elemer, Oct 26 2004

Keywords

• base
• nonn

Comments

Contrary to A099629, this sequence is evidently infinite. Essentially [for more than 2 digits] consists of pairs of {nextprime[10^j],prevprime[10^(j+1)]}.

Crossrefs

Cf. A098224-A098227.

Programs

Mathematica

Join[{11,11},Flatten[Table[{NextPrime[10^n],NextPrime[10^(n+1),-1]}, {n,2,20}]]] (* Harvey P. Dale, Jun 04 2018 *)

Extensions

Corrected and extended by Harvey P. Dale, Jun 04 2018