OFFSET
1,1
COMMENTS
if n = A007510(k) (Single primes), then a(n) = 0.
EXAMPLE
a(6) = 0 because there is no prime p such that 6*p + 1 is a square.
a(11) = 13 because 11*13 + 1 = 144 is a square.
MAPLE
with(numtheory): for k from 1 to 120 do : q:=0:for p from 1 to 200 do : x:=sqrt(k*p+1)
: if x=trunc(x) and type(p, prime)=true and q=0 then q:=1: printf(`%d, `, p):else
fi:od:if q=0 then printf(`%d, `, q):else fi:od:
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Michel Lagneau, Mar 15 2011
STATUS
approved