A247096 Numbers n such that (n^2 - 2) and (n^2 + 2) are not squarefree.

58, 59, 157, 284, 338, 373, 382, 500, 598, 725, 745, 823, 843, 941, 1039, 1111, 1166, 1201, 1264, 1382, 1400, 1480, 1490, 1607, 1705, 1732, 1823, 1921, 1999, 2038, 2048, 2146, 2264, 2272, 2362, 2489, 2587, 2686, 2705, 2767, 2803, 2930, 3028, 3146, 3244, 3371, 3469, 3547, 3587, 3685, 3712

Offset: 1

Author

Juri-Stepan Gerasimov, Nov 18 2014

Keywords

• nonn

Comments

Intersection of A227897 and A228140.

Primes: 59, 157, 373, 823, 941, 1039, 1201, 1607, 1823, 1999, 2767, 2803, 3371, 3469, 3547, ...

Links

• Colin Barker, Table of n, a(n) for n = 1..1000

Crossrefs

Cf. A227897, A228140.

Programs

Magma

[n: n in [1..4000] | not IsSquarefree(n^2 - 2) and not IsSquarefree(n^2 + 2)];

Mathematica

Select[Range[4000],! SquareFreeQ[#^2 - 2] && ! SquareFreeQ[#^2 + 2] &] (* Vincenzo Librandi, Nov 18 2014 *)

PARI

select(n->!issquarefree(n^2-2) && !issquarefree(n^2+2), vector(4000, n, n)) \\ Colin Barker, Nov 18 2014