OFFSET
1,1
COMMENTS
From Jeppe Stig Nielsen, Jul 07 2020: (Start)
Each term is -1 modulo 210.
The subset p, 2p+1, 4p+3, 8p+7 is a Cunningham chain, cf. A023272. (End)
LINKS
Robert Israel, Table of n, a(n) for n = 1..250 (first 50 terms from Jeppe Stig Nielsen)
Wikipedia, Cunningham chain
MAPLE
R:= NULL: count:= 0:
for i from 0 while count < 50 do
for j in [1049, 2099, 2309] do
p:= 2310*i+j;
if andmap(isprime, [p, 2*p + 1, 3*p + 2, 4*p + 3, 5*p + 4, 6*p + 5, 7*p + 6, 8*p + 7]) then
count:= count+1; R:= R, p;
fi
od od:
R; # Robert Israel, May 21 2025
MATHEMATICA
a={}; Do[p=Prime[n]; If[PrimeQ[p*2+1]&&PrimeQ[p*3+2]&&PrimeQ[p*4+3]&&PrimeQ[p*5+4]&&PrimeQ[p*6+5]&&PrimeQ[p*7+6]&&PrimeQ[p*8+7], AppendTo[a, p]], {n, 1, 10^7}]; Print[a]; (* Vladimir Joseph Stephan Orlovsky, Apr 29 2008 *)
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Jonathan Vos Post and Ray Chandler, Dec 31 2004
EXTENSIONS
a(20)-a(22) from Jeppe Stig Nielsen, Jul 07 2020
STATUS
approved
