OFFSET
1,1
COMMENTS
There are some twin primes in the sequence: (3,5); (239,241); (419, 421); (1607, 1609).
Apparently the sequence is infinite.
LINKS
Robert Israel, Table of n, a(n) for n = 1..10000
EXAMPLE
a(5)=29 since 29*(31+1)+1=29*32+1=929 is a prime.
MAPLE
R:= NULL; count:= 0:
q:= 2:
while count < 100 do
p:= q; q:= nextprime(q);
if isprime(p*(q+1)+1) then count:= count+1; R:= R, p fi
od:
R; # Robert Israel, May 12 2020
MATHEMATICA
Select[Prime[Range[350]], PrimeQ[ # (NextPrime[ # ]+1)+1]&] (* Harvey P. Dale, Oct 08 2010 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Carmine Suriano, Sep 26 2010
EXTENSIONS
Added missing terms (5 terms were omitted after 887). Harvey P. Dale, Oct 08 2010
STATUS
approved