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A179917
Primes with nine embedded primes.
2
11317, 19739, 19973, 21317, 21379, 22397, 22937, 23117, 23173, 23371, 23971, 24373, 26317, 27197, 29173, 29537, 32719, 33739, 33797, 37397, 39719, 51137, 51973, 52313, 53173, 53479, 53719, 57173, 57193, 61379, 61979, 63179, 66173
OFFSET
1,1
COMMENTS
A079066(a(n)) = 9.
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@ 6610, f@# == 10 &]
PROG
(Haskell)
import Data.List (elemIndices)
a179917 n = a179917_list !! (n-1)
a179917_list = map (a000040 . (+ 1)) $ elemIndices 9 a079066_list
-- Reinhard Zumkeller, Jul 19 2011
KEYWORD
base,nonn
AUTHOR
Robert G. Wilson v, Aug 01 2010
STATUS
approved