A179915 Primes with seven embedded primes.

1373, 3137, 3797, 5237, 6173, 11173, 11311, 11353, 11719, 11731, 11971, 12113, 12239, 12347, 12377, 12953, 12973, 13127, 13177, 13217, 13537, 13597, 13679, 13709, 13711, 13723, 13729, 13751, 13757, 13759, 13799, 13967, 13997, 15137

Offset: 1

Author

Robert G. Wilson v, Aug 01 2010

Keywords

• base
• nonn

Comments

A079066(a(n)) = 7.

Crossrefs

Cf. A039996, A079397, A033274, A034844, A092621, A179909 - A179919, A033274.

Programs

Haskell

import Data.List (elemIndices)
a179915 n = a179915_list !! (n-1)
a179915_list = map (a000040 . (+ 1)) $ elemIndices 7 a079066_list
-- Reinhard Zumkeller, Jul 19 2011

Mathematica

f[n_] := Block[ {id = IntegerDigits@n}, len = Length@ id - 1; Count[ PrimeQ@ Union[ FromDigits@# & /@ Flatten[ Table[ Partition[ id, k, 1], {k, len}], 1]], True] + 1]; Select[ Prime@ Range@ 1770, f@# == 8 &]