A100633 - OEIS

%I #4 Mar 30 2012 17:31:07

%S 257,523,1123,1153,1327,1373,1723,1753,1973,2113,2137,2237,2293,2297,

%T 2311,2341,2347,2357,2371,2377,2383,2389,2417,2437,2473,2477,2531,

%U 2543,2579,2593,2617,2677,2711,2713,2719,2729,2731,2741,2753,2767,2789,2797

%N Primes that are the decimal concatenation of three separate primes.

%t (*first do *) Needs["DiscreteMath`Combinatorica`"] (* then *) t = KSubsets[ Prime[ Range[25]], 3]; lst = {}; Do[k = 1; u = Permutations[ t[[n]]]; While[k < 7, v = FromDigits[ Flatten[IntegerDigits /@ u[[k]]]]; If[ PrimeQ[v], AppendTo[lst, v]]; k++ ], {n, Binomial[25, 3]}]; Take[ Union[lst], 42]

%Y Cf. A100607.

%K nonn,base

%O 1,1

%A _Robert G. Wilson v_, Dec 03 2004

%E Edited by _Charles R Greathouse IV_, Apr 29 2010