OFFSET
1,1
COMMENTS
7+11+13+17+19=67(prime);19+23+29+31+37=139(prime),... prime(n)+prime(n-1)+prime(n-2)+prime(n-3)+prime(n-4) are primes and prime(n)+prime(n+1)+prime(n+2)+prime(n+3)+prime(n+4) are also primes.
LINKS
Harvey P. Dale, Table of n, a(n) for n = 1..1000
MATHEMATICA
lst={}; Do[p0=Prime[n+0]; p1=Prime[n+1]; p2=Prime[n+2]; p3=Prime[n+3]; p4=Prime[n+4]; p5=Prime[n+5]; p6=Prime[n+6]; p7=Prime[n+7]; p8=Prime[n+8]; If[PrimeQ[p0+p1+p2+p3+p4]&&PrimeQ[p4+p5+p6+p7+p8], AppendTo[lst, p4]], {n, 7!}]; lst
Transpose[Select[Partition[Prime[Range[500]], 9, 1], And@@PrimeQ[{Total[ Take[#, 5]], Total[Take[#, -5]]}]&]][[5]] (* Harvey P. Dale, Jul 11 2013 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Vladimir Joseph Stephan Orlovsky, Feb 15 2009
STATUS
approved