cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A275682 Table read by rows: list of sexy prime quadruples (p, p+6, p+12, p+18) such that p+24 is composite.

Original entry on oeis.org

11, 17, 23, 29, 41, 47, 53, 59, 61, 67, 73, 79, 251, 257, 263, 269, 601, 607, 613, 619, 641, 647, 653, 659, 1091, 1097, 1103, 1109, 1481, 1487, 1493, 1499, 1601, 1607, 1613, 1619, 1741, 1747, 1753, 1759, 1861, 1867, 1873, 1879, 2371, 2377, 2383, 2389
Offset: 1

Views

Author

Arkadiusz Wesolowski, Aug 05 2016

Keywords

Comments

(5, 11, 17, 23, 29) is a sexy prime 5-tuple and this is the only sexy prime 5-tuple.
Essentially same as A123083.

Examples

			The table starts:
11, 17, 23, 29;
41, 47, 53, 59;
61, 67, 73, 79;
...
		

Crossrefs

Programs

  • Magma
    lst:=[]; for p in PrimesInInterval(7, 2371) do b:=p+6; if IsPrime(b) then c:=b+6; if IsPrime(c) then d:=c+6; if IsPrime(d) then lst:=lst cat [p, b, c, d]; end if; end if; end if; end for; lst;
  • Mathematica
    Most[#]&/@Select[Table[n + {0, 6, 12, 18, 24}, {n, Prime[Range[200]]}], PrimeQ[#]=={True, True, True, True, False}&]//Flatten (* Vincenzo Librandi, Jun 09 2017 *)
    #+{0,6,12,18}&/@Select[Prime[Range[400]],AllTrue[#+{6,12,18},PrimeQ] && CompositeQ[#+24]&]//Flatten (* The program uses the AllTrue function from Mathematica version 10 *) (* Harvey P. Dale, Apr 29 2019 *)

Formula

a(n) = A123083(n+4).