A187113 Primes of the form abcdabcd..abcda.

10061, 10091, 10111, 10141, 10151, 10181, 10211, 10271, 10301, 10321, 10331, 10391, 10501, 10531, 10601, 10631, 10651, 10691, 10711, 10771, 10781, 10831, 10861, 10891, 11071, 11131, 11161, 11171, 11251, 11261, 11311, 11321, 11351, 11411, 11471, 11491, 11551

Offset

1,1

Comments

The sequence appears to be infinite. The number of terms below 10^1000 are 5749.

Links

Shyam Sunder Gupta, Table of n, a(n) for n = 1..3032

Example

a(2)= 10091 is in the sequence because it is a prime of the form abcda.

Mathematica

s[n_]:=Select[Union@Flatten@Table[FromDigits@Flatten@Join[IntegerDigits@Table[b, {n}], {IntegerDigits@Floor[b/1000]}], {b, 1000, 9999}], PrimeQ]; Array[s, 2]//Flatten

Crossrefs

Cf. A228625, A228627

Sequence in context: A250711 A223431 A203089 * A023356 A292176 A198484

Adjacent sequences: A187110 A187111 A187112 * A187114 A187115 A187116

Keyword

nonn,base

Author

Shyam Sunder Gupta, Aug 30 2013

Status

approved