OFFSET
1,2
COMMENTS
LINKS
Michael De Vlieger, Table of n, a(n) for n = 1..10000
MATHEMATICA
(Select[Prime@ Range[3, 720], And[SquareFreeQ[(# + 1)/2], PrimeQ[# + 2]] &] + 1)/6 (* Michael De Vlieger, Jul 25 2022 *)
PROG
(PARI) isok(k) = issquarefree(k) && isprime(2*k-1) && isprime(2*k+1); \\ A066653
lista(nn) = my(list = List()); for (n=3, nn, if (isok(n), listput(list, n/3)); ); Vec(list); \\ Michel Marcus, Jul 25 2022
CROSSREFS
KEYWORD
nonn
AUTHOR
Wesley Ivan Hurt, Jul 18 2022
STATUS
approved