OFFSET
1,1
COMMENTS
Also: k such that A033570(k) is semiprime. All terms are congruent to 0 or 2 modulo 6. - M. F. Hasler, Dec 13 2019
LINKS
Harvey P. Dale, Table of n, a(n) for n = 1..1000
FORMULA
a(n) = 2*A255607(n). - M. F. Hasler, Dec 13 2019
MATHEMATICA
Select[Range[1100], AllTrue[{2, 3}#+1, PrimeQ]&] (* The program uses the AllTrue function from Mathematica version 10 *) (* Harvey P. Dale, May 17 2016 *)
PROG
(Magma) [n: n in [0..500] | IsPrime(2*n+1) and IsPrime(3*n+1)]; // Vincenzo Librandi, Nov 23 2010
(PARI) select( is_A130800(n)=isprime(2*n+1)&&isprime(3*n+1), [1..1111]) \\ M. F. Hasler, Dec 13 2019
CROSSREFS
KEYWORD
nonn
AUTHOR
Max Alekseyev, Jul 18 2007
EXTENSIONS
More terms from Vincenzo Librandi, Mar 26 2010
STATUS
approved