OFFSET
1,1
EXAMPLE
a(1) = 1036 because 1036 is composite, the six permutations 163, 613, 631, 1063, 3061, and 6301 are all prime, and no other permutation of 1036 is prime.
MATHEMATICA
Select[Range[2000], CompositeQ[#]&&Count[FromDigits/@Permutations[ IntegerDigits[ #]], _?PrimeQ]==6&] (* Harvey P. Dale, Mar 05 2023 *)
CROSSREFS
KEYWORD
easy,nonn,base
AUTHOR
Gil Broussard, Jul 30 2009
STATUS
approved