A129900 Primes p such that 10*p + q is a prime, where q is the smallest prime > p.

2, 31, 47, 61, 73, 83, 131, 151, 157, 211, 251, 257, 353, 383, 557, 563, 571, 593, 661, 733, 797, 941, 971, 977, 997, 1013, 1033, 1063, 1069, 1097, 1187, 1237, 1291, 1307, 1321, 1459, 1511, 1543, 1613, 1621, 1657, 1741, 1753, 1777

Offset

1,1

Links

Harvey P. Dale, Table of n, a(n) for n = 1..1000

Example

1097 is a prime, and the next prime is 1103. 10*1097 + 1103 = 12073, which is prime.

Mathematica

Select[Prime[Range[1000]], PrimeQ[10*# + Prime[PrimePi[ # ] + 1]] &]
Select[Prime[Range[1000]], PrimeQ[10#+NextPrime[#]]&] (* Harvey P. Dale, Jun 12 2014 *)

Crossrefs

Sequence in context: A241484 A235477 A370157 * A262834 A376205 A229206

Adjacent sequences: A129897 A129898 A129899 * A129901 A129902 A129903

Keyword

nonn

Author

J. M. Bergot, Jun 04 2007

Extensions

Edited, corrected and extended by Stefan Steinerberger, Jul 21 2007

Status

approved