OFFSET
1,1
LINKS
Harvey P. Dale, Table of n, a(n) for n = 1..1000
FORMULA
For positive n: {Concatenate((2n+1), (2n+3), (2n+5), (2n+7))} Intersect {Primes A000040}.
MATHEMATICA
Select[FromDigits/@(Flatten[IntegerDigits[#]]&/@Partition[Range[ 1, 501, 2], 4, 1]), PrimeQ] (* Harvey P. Dale, Jul 18 2013 *)
CROSSREFS
KEYWORD
base,easy,nonn
AUTHOR
Jonathan Vos Post, Apr 12 2005
STATUS
approved