OFFSET
1,1
COMMENTS
Variation on Schinzel's Hypothesis.
LINKS
Paolo P. Lava, Table of n, a(n) for n = 1..1000
Eric Weisstein's World of Mathematics, Schinzel's Hypothesis.
EXAMPLE
For n=1 the minimum primes p and q are 5 and 3: (p-1)/(q+1) = (5-1)/(3+1) = 4/4 = 1. Therefore a(1)=5.
For n=2 the minimum primes p and q are 7 and 2: (p-1)/(q+1) = (7-1)/(2+1) = 6/3 = 2. Therefore a(2)=7. Etc.
MAPLE
with(numtheory): P:=proc(q) local k, n;
for n from 1 to q do for k from 1 to q do
if isprime(n*(ithprime(k)+1)+1) then print(n*(ithprime(k)+1)+1);
break; fi; od; od; end: P(10^5);
PROG
(PARI) a(n) = my(q=2); while(! isprime(p=n*(q+1)+1), q = nextprime(q+1)); p; \\ Michel Marcus, Nov 07 2014
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Paolo P. Lava, Nov 06 2014
STATUS
approved