A155140 Primes p such that both p-+4 are not squarefree.

293, 347, 571, 829, 1021, 1229, 1327, 1373, 1471, 1621, 2111, 2129, 2371, 2531, 2579, 2879, 2887, 3181, 3271, 3929, 4621, 4801, 4909, 5279, 5333, 5521, 5639, 5683, 5827, 6133, 6421, 6521, 6709, 6863, 6871, 7079, 7321, 7529, 7591, 8179, 8221, 8429, 8963

Offset

1,1

Links

John Cerkan, Table of n, a(n) for n = 1..10000

Mathematica

<<NumberTheory`NumberTheoryFunctions` lst={}; Do[p=Prime[n]; If[ !SquareFreeQ[p-4]&&!SquareFreeQ[p+4], AppendTo[lst, p]], {n, 7!}]; lst
Select[Prime[Range[1200]], NoneTrue[#+{4, -4}, SquareFreeQ]&] (* Harvey P. Dale, Jul 17 2024 *)

Prog

(PARI) lista(nn) = forprime(p=2, nn, if (! issquarefree(p-4) && ! issquarefree(p+4), print1(p, ", "))); \\ Michel Marcus, Jul 05 2016

Crossrefs

Cf. A153213, A049282, A155139, A155141, A155142.

Sequence in context: A232280 A202888 A217181 * A248210 A142284 A245583

Adjacent sequences: A155137 A155138 A155139 * A155141 A155142 A155143

Keyword

nonn

Author

Vladimir Joseph Stephan Orlovsky, Jan 21 2009

Status

approved