A086709 Primes p such that p-1 and p+1 are both divisible by fourth powers.

1249, 2753, 3727, 4049, 4801, 5023, 7937, 10529, 11503, 12799, 13121, 15391, 20897, 21871, 22193, 23167, 25759, 28351, 28751, 31249, 32561, 33857, 35153, 37423, 39041, 42929, 46817, 47791, 48751, 49409, 50383, 51679, 55889, 58481, 62047

Offset

1,1

Links

Amiram Eldar, Table of n, a(n) for n = 1..10000 (terms 1..2000 from Vincenzo Librandi)

Mathematica

f[n_]:=Max[Last/@FactorInteger[n]]; lst={}; Do[p=Prime[n]; If[f[p-1]>=4&&f[p+1]>=4, AppendTo[lst, p]], {n, 8!}]; lst (* Vladimir Joseph Stephan Orlovsky, Oct 03 2009 *)
dfpQ[n_]:=Max[Transpose[FactorInteger[n]][[2]]]>3; Select[Prime[Range[ 6500]], dfpQ[#-1]&&dfpQ[#+1]&] (* Harvey P. Dale, May 11 2012 *)

Crossrefs

Cf. A046101, A075432, A086708, A089212.

Sequence in context: A233244 A233222 A020384 * A215719 A120376 A231805

Adjacent sequences: A086706 A086707 A086708 * A086710 A086711 A086712

Keyword

nonn

Author

Amarnath Murthy, Jason Earls, Jul 28 2003

Status

approved