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A179909 Primes with only one embedded prime. 15

%I #7 Jul 13 2013 12:03:43

%S 13,17,29,31,43,47,59,67,71,79,83,97,103,107,151,163,191,199,269,281,

%T 349,421,461,463,487,509,569,607,641,661,701,709,769,787,811,821,863,

%U 877,887,907,911,919,941,1021,1051,1061,1063,1087,1091,1201,1249,1409

%N Primes with only one embedded prime.

%C A079066(a(n)) = 1.

%H Reinhard Zumkeller, <a href="/A179909/b179909.txt">Table of n, a(n) for n = 1..1000</a>

%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@ 230, f@# == 2 &]

%o (Haskell)

%o import Data.List (elemIndices)

%o a179909 n = a179909_list !! (n-1)

%o a179909_list = map (a000040 . (+ 1)) $ elemIndices 1 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 24 16:49 EDT 2024. Contains 371962 sequences. (Running on oeis4.)