OFFSET
1,1
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..10000
FORMULA
a(n) = 12*A154331(n)^2. - M. F. Hasler, Jan 15 2009
EXAMPLE
12*3 = 36 = 6^2, 12/3 = 4 = 2^2.
MATHEMATICA
lst={}; Do[If[PrimeQ[n-1]&&PrimeQ[n+1], s=(n*3)^(1/2); If[Floor[s]==s, AppendTo[lst, n]]], {n, 6, 10!, 6}]; lst...and/or... lst={}; Do[If[PrimeQ[n-1]&&PrimeQ[n+1], s=(n/3)^(1/2); If[Floor[s]==s, AppendTo[lst, n]]], {n, 6, 10!, 6}]; lst
Select[Mean/@Select[Partition[Prime[Range[150000]], 2, 1], #[[2]]-#[[1]] == 2&], AllTrue[{Sqrt[#/3], Sqrt[3#]}, IntegerQ]&] (* The program uses the AllTrue function from Mathematica version 10 *) (* Harvey P. Dale, Dec 06 2015 *)
PROG
(PARI) for(i=1, 999, isprime(12*i^2+1) && isprime(12*i^2-1) && print1(12*i^2", ")) \\ M. F. Hasler, Jan 15 2009
CROSSREFS
KEYWORD
nonn
AUTHOR
Vladimir Joseph Stephan Orlovsky, Jan 13 2009
STATUS
approved