OFFSET
1,1
COMMENTS
Balanced primes separated from the next lower and next higher prime neighbors by 6.
Subset of A006489. - R. J. Mathar, Apr 11 2008
Subset of A006562. - Zak Seidov, Feb 14 2013
a(n) == {3,7} mod 10. - Zak Seidov, Feb 14 2013
Minimal difference is 6: a(5) - a(4) = 263 - 257, a(20) - a(19) = 1753 - 1747, ... . - Zak Seidov, Feb 14 2013
LINKS
Harvey P. Dale, Table of n, a(n) for n = 1..1000
FORMULA
a(n) = A047948(n) + 6. - R. J. Mathar, Apr 11 2008
EXAMPLE
157 is separated from both the next lower prime, 151 and the next higher prime, 163, by 6.
MAPLE
for i from 1 by 1 to 800 do if ithprime(i+1) = ithprime(i) + 6 and ithprime(i+2) = ithprime(i) + 12 then print(ithprime(i+1)); fi; od; # Zerinvary Lajos, Apr 27 2007
MATHEMATICA
lst={}; Do[p=Prime[n]; If[p-Prime[n-1]==Prime[n+1]-p==6, AppendTo[lst, p]], {n, 2, 7!}]; lst (* Vladimir Joseph Stephan Orlovsky, May 20 2010 *)
Transpose[Select[Partition[Prime[Range[1000]], 3, 1], Differences[#]=={6, 6}&]][[2]] (* Harvey P. Dale, Oct 11 2012 *)
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Harvey P. Dale, Feb 25 2000
EXTENSIONS
Edited by N. J. A. Sloane at the suggestion of Zak Seidov, Apr 09 2008
STATUS
approved