A187114 Primes of the form abcdabcd..abcdab.

110311, 110711, 111211, 111611, 112111, 113011, 113111, 114311, 115211, 115811, 116411, 116911, 117511, 117811, 117911, 118211, 118411, 119311, 119611, 130513, 131113, 131213, 131413, 131713, 132113, 132313, 133013, 133213, 133813, 134213, 134513, 135613

Offset

1,1

Comments

The sequence appears to be infinite. The number of terms below 10^1000 are 5211.

Links

Shyam Sunder Gupta, Table of n, a(n) for n = 1..2711

Example

a(2)= 110711 is in the sequence because it is a prime of the form abcdab.

Mathematica

s[n_]:=Select[Union@Flatten@Table[FromDigits@Flatten@Join[IntegerDigits@Table[b, {n}], {IntegerDigits@Floor[b/100]}], {b, 1000, 9999}], PrimeQ]; Array[s, 2]//Flatten

Crossrefs

Cf. A228625, A228627

Sequence in context: A138722 A122240 A250591 * A145872 A254853 A250533

Adjacent sequences: A187111 A187112 A187113 * A187115 A187116 A187117

Keyword

nonn,base

Author

Shyam Sunder Gupta, Aug 30 2013

Status

approved