A078957 Primes p such that the differences between the 5 consecutive primes starting with p are (4,6,6,6).
12637, 14737, 15787, 17467, 78787, 95257, 104707, 120997, 154057, 243517, 250027, 252877, 351037, 357667, 443227, 496477, 501187, 593497, 624787, 696607, 750787, 917827, 949957, 1003087, 1025257, 1104097, 1109887, 1260877, 1279657, 1457857, 1517917, 1565167, 1654717
Offset: 1
Keywords
Examples
15787 is in the sequence since 15787, 15791 = 15787 + 4, 15797 = 15787 + 10, 15803 = 15787 + 16 and 15809 = 15787 + 22 are consecutive primes.
Links
- Amiram Eldar, Table of n, a(n) for n = 1..10000 (terms 1..1000 from Harvey P. Dale)
Programs
-
Mathematica
Select[Partition[Prime[Range[10^5]],5,1],Differences[#]=={4,6,6,6}&][[All,1]] (* Harvey P. Dale, Jun 23 2019 *)
-
PARI
list(lim) = {my(p1 = 2, p2 = 3, p3 = 5, p4 = 7); forprime(p5 = 11, lim, if(p2 - p1 == 4 && p3 - p2 == 6 && p4 - p3 == 6 && p5 - p4 == 6, print1(p1, ", ")); p1 = p2; p2 = p3; p3 = p4; p4 = p5);} \\ Amiram Eldar, Feb 21 2025
Formula
a(n) == 7 (mod 30). - Amiram Eldar, Feb 21 2025
Extensions
Edited by Dean Hickerson, Dec 20 2002
Comments