A179912 - OEIS

%I #6 Feb 22 2013 21:38:32

%S 137,173,317,373,379,523,673,1123,1153,1171,1193,1223,1231,1277,1279,

%T 1283,1297,1307,1327,1531,1579,1597,1613,1637,1759,1783,1823,1913,

%U 1931,2053,2153,2333,2339,2341,2351,2393,2399,2411,2467,2503,2539,2543,2557

%N Primes with four embedded primes.

%C A079066(a(n)) = 4.

%t 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@ 380, f@# == 5 &]

%o (Haskell)

%o import Data.List (elemIndices)

%o a179912 n = a179912_list !! (n-1)

%o a179912_list = map (a000040 . (+ 1)) $ elemIndices 4 a079066_list

%o -- _Reinhard Zumkeller_, Jul 19 2011

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

%K base,nonn

%O 1,1

%A _Robert G. Wilson v_, Aug 01 2010