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.

A342502 Gaps between first elements of prime quintuples of the form (p, p+2, p+6, p+12, p+14). The quintuples are abutting: twin/cousin/sexy/twin pairs.

Original entry on oeis.org

12, 210, 1050, 330, 1920, 390, 720, 150, 22950, 10710, 780, 5040, 27060, 26040, 2340, 13440, 8880, 360, 1950, 41370, 17790, 3630, 4320, 6510, 870, 76620, 15210, 21540, 5760, 29100, 2340, 66990, 1950, 3360, 5370, 16800, 6930, 40530, 4230, 3570, 15510, 10320
Offset: 1

Views

Author

James S. DeArmon, Mar 14 2021

Keywords

Examples

			The first 4 terms of the sequence are 12, 210, 1050, 330, since the gaps between first elements of the first five quintuples {5,7,11,17,19}, {17,19,23,29,31}, {227,229,233,239,241}, {1277,1279,1283,1289,1291}, {1607,1609,1613,1619,1621} are, 17-5=12, 227-17=210, etc.
		

Crossrefs

Cf. A078946.

Programs

  • Maple
    b:= proc(n) option remember; local p; p:= `if`(n=1, 1, b(n-1));
          do p:= nextprime(p);
             if andmap(isprime, [p+2, p+6, p+12, p+14]) then return p fi
          od
        end:
    a:= n-> b(n+1)-b(n):
    seq(a(n), n=1..65);  # Alois P. Heinz, Mar 14 2021
  • Mathematica
    b[n_] := b[n] = Module[{p}, p = If[n == 1, 1, b[n-1]]; While[True, p = NextPrime[p]; If[AllTrue[{p+2, p+6, p+12, p+14}, PrimeQ], Return[p]]]];
    a[n_] := b[n+1]-b[n];
    Table[a[n], {n, 1, 65}] (* Jean-François Alcover, May 14 2022, after Alois P. Heinz *)

Formula

a(n) = A078946(n) - A078946(n-1) for n >= 2.
a(n) == 0 (mod 30) for n>1.