A166003 Primes p such that p+-1, p+-2 and p+-3 are not squarefree.

47527, 186247, 218527, 245149, 269953, 377543, 390449, 432277, 447823, 453053, 469649, 518123, 568177, 584911, 589273, 606323, 632347, 661547, 761347, 831751, 848213, 897577, 913327, 925949, 952253, 1172351, 1205647, 1220347, 1241477

Offset: 1

Author

Vladimir Joseph Stephan Orlovsky, Oct 03 2009

Keywords

• nonn

Links

• Amiram Eldar, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A086708, A086709, A089199, A089200, A089212, A166000, A166001, A166002.

Programs

Mathematica

f[n_]:=Max[Last/@FactorInteger[n]]; q=2;lst={};Do[p=Prime[n];If[f[p-3]>=q&&f[p-2]>=q&&f[p-1]>=q&&f[p+1]>=q&&f[p+2]>=q&&f[p+3]>=q,AppendTo[lst,p]],{n,6*8!}];lst
Select[Prime[Range[100000]],NoneTrue[#+{-3,-2,-1,1,2,3},SquareFreeQ]&] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Apr 17 2018 *)

Extensions

Edited by N. J. A. Sloane, Oct 04 2009