OFFSET
1,1
COMMENTS
Leading zeros in the permutations are ignored.
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 1..5200
Cino Hilliard, Comments and PARI program.
Wikipedia, Permutation
EXAMPLE
1013 has eight permutations of its digits 1, 0, 1, 3 that form a prime, namely 113, 131, 311, 1013, 1031, 1103, 1301, 3011. So the count of primes for 1013 is greater than 7 and 1013 is in the sequence.
MATHEMATICA
Select[Range[2000], Count[FromDigits/@Permutations[IntegerDigits[#]], _?PrimeQ]>7&] (* Vincenzo Librandi, Feb 02 2018 *)
PROG
(PARI) See Hilliard link.
(Magma) [ n: n in [1..1500] | #[ s: s in Seqset([ Seqint([m(p[i]):i in [1..#x] ], 10): p in Permutations(Seqset(x)) ]) | IsPrime(s) ] gt 7 where m is map< x->y | [<x[i], y[i]>:i in [1..#x] ] > where x is [1..#y] where y is Intseq(n, 10) ]; // Klaus Brockhaus, Jun 14 2009
CROSSREFS
KEYWORD
base,nonn
AUTHOR
Cino Hilliard, Jun 09 2009
EXTENSIONS
Edited by Klaus Brockhaus, Jun 14 2009
STATUS
approved