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A179915 Primes with seven embedded primes. 2

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

%S 1373,3137,3797,5237,6173,11173,11311,11353,11719,11731,11971,12113,

%T 12239,12347,12377,12953,12973,13127,13177,13217,13537,13597,13679,

%U 13709,13711,13723,13729,13751,13757,13759,13799,13967,13997,15137

%N Primes with seven embedded primes.

%C A079066(a(n)) = 7.

%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@ 1770, f@# == 8 &]

%o (Haskell)

%o import Data.List (elemIndices)

%o a179915 n = a179915_list !! (n-1)

%o a179915_list = map (a000040 . (+ 1)) $ elemIndices 7 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

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Last modified April 27 14:49 EDT 2024. Contains 372019 sequences. (Running on oeis4.)