A088639 -id:A088639 - cp's OEIS frontend

A068120 Smallest prime beginning with exactly n n's.

13, 223, 3331, 44449, 555557, 66666629, 777777701, 888888883, 99999999907, 1010101010101010101039, 11111111111111111111111, 12121212121212121212121223, 1313131313131313131313131301, 141414141414141414141414141497, 15151515151515151515151515151501

Offset: 1

Amarnath Murthy, Feb 21 2002

A probabilistic argument suggests that this sequence will cease to be monotonically increasing around n = 10^8. - Martin Fuller, Jan 29 2007

Sean A. Irvine, Table of n, a(n) for n = 1..100 (terms 1..35 from Jacques Tramu and Dan Dima)

See A088639 for another version.

Corrected and extended by Jacques Tramu, Jan 27 2007

A088640 Smallest number suffixed to concatenation of n times n gives a prime.

Original entry on oeis.org

2, 1, 3, 1, 9, 7, 29, 1, 3, 7, 39, 1, 23, 1, 97, 1, 91, 37, 59, 9, 93, 19, 97, 61, 293, 61, 3, 1, 57, 7, 43, 61, 7, 53, 31, 127, 353, 67, 841, 187, 9, 3, 179, 429, 127, 97, 3, 319, 11, 51, 39, 191, 33, 3, 41, 7, 39, 47, 73, 81, 401, 57, 441, 571, 957, 997, 1, 19, 291, 173, 9, 417

Offset: 0

Amarnath Murthy, Oct 27 2003

			a(6) = 29 and 66666629 is prime.

Cf. A088639.

a:= proc(n) local d, h, s;
      s:= parse(cat(0, n$n));
      for d from 0 do
        for h to 10^d-1 do
          if isprime(s+h) then return h fi
        od:
        s:= s*10;
      od
    end:
seq(a(n), n=0..75);  # Alois P. Heinz, Feb 11 2021

More terms from Ray Chandler, Nov 01 2003

a(0)=2 prepended by Alois P. Heinz, Feb 11 2021

cp's OEIS Frontend

A068120 Smallest prime beginning with exactly n n's.

Views

Author

Keywords

Comments

Links

Crossrefs

Extensions

A088640 Smallest number suffixed to concatenation of n times n gives a prime.

Views

Author

Keywords

Examples

Crossrefs

Programs

Maple

Extensions