OFFSET
1,2
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..10000
Stoyan Ivanov Dimitrov, Square-free values of n^2+n+1, Georgian Mathematical Journal, Vol. 30, No. 3 (2023), pp. 333-348; arXiv preprint, arXiv:2205.02488 [math.NT], 2022-2023.
EXAMPLE
4^2 + 4 + 1 = 21 = 3 * 7 is squarefree, so 21 belongs to this sequence.
MATHEMATICA
Select[Table[n^2 + n + 1, {n, 0, 52}], SquareFreeQ] (* Amiram Eldar, Dec 11 2023 *)
PROG
(PARI) for (k=0, 52, if (issquarefree(m=k^2+k+1), print1 (m", ")))
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Rémy Sigrist, May 09 2022
STATUS
approved