A070219 Smallest prime obtained as a concatenation of n and a number m greater than n.

13, 23, 37, 47, 59, 67, 79, 89, 911, 1013, 1117, 1213, 1319, 1423, 1523, 1619, 1721, 1823, 1931, 2027, 2129, 2237, 2333, 2437, 2531, 2633, 2729, 2833, 2939, 3037, 3137, 3251, 3343, 3449, 3539, 3637, 3739, 3847, 3943, 4049, 4153, 4243, 4349, 4447, 4547

Offset

1,1

Comments

If we change the definition to m >= n, then a(1) becomes 11, but nothing else changes.

Conjectures: There is at least one number k with n<k<2n such that the concatenation n and n+k is a prime. For all m there is at least one number k with m*n < k < (m+1)*n such that the concatenation n and n+k is a prime.

Links

Table of n, a(n) for n=1..45.

Crossrefs

Cf. A089713, A089715.

Sequence in context: A089777 A050857 A089714 * A046119 A164416 A164491

Adjacent sequences: A070216 A070217 A070218 * A070220 A070221 A070222

Keyword

base,nonn

Author

Amarnath Murthy, Nov 17 2003

Extensions

Edited by David Wasserman, Feb 05 2004

Further edited by N. J. A. Sloane, Oct 21 2008 at the suggestion of R. J. Mathar

Status

approved