OFFSET
1,1
COMMENTS
Sum and difference of any of two consecutive numbers in current sequence are prime numbers and multiplication and any two consecutive numbers is Average of twin prime pairs : 9-2=7;9+2=11;9*2=18, ...
LINKS
Robert Israel, Table of n, a(n) for n = 1..10000
MAPLE
A:= 2, 9: b:= 9:
for i from 3 to 100 do
p:= 2:
do
p:= nextprime(p);
k:= b + p;
if isprime(b*k+1) and isprime(b*k-1) and isprime(k+b) then
A:= A, k; b:= k; break
fi od od:
A; # Robert Israel, Jan 01 2024
MATHEMATICA
a=2; b=9; lst={a, b}; Do[If[PrimeQ[n-b]&&PrimeQ[n+b]&&PrimeQ[n*b-1]&&PrimeQ[n*b+1], AppendTo[lst, n]; a=b; b=n], {n, b+1, 9!}]; lst
CROSSREFS
KEYWORD
nonn
AUTHOR
Vladimir Joseph Stephan Orlovsky, Jan 10 2009
EXTENSIONS
NAME adapted to offset. - R. J. Mathar, Jun 19 2021
STATUS
approved