|
|
A339945
|
|
Numbers y such that sqrt(6*y^2+10)-3 is prime.
|
|
2
|
|
|
|
OFFSET
|
1,1
|
|
COMMENTS
|
sqrt(p + (p^2-1)/6) for p in A339935.
Primes in this sequence include 3, 13, 31. Are there any others?
|
|
LINKS
|
|
|
EXAMPLE
|
a(3) = 31 is a term because sqrt(6*31^2+10)-3 = 73 is prime.
|
|
MAPLE
|
g:= gfun:-rectoproc({a(i+4)-10*a(i+2)+a(i)=0, a(0)=1, a(1)=3, a(2)=13, a(3)= 31}, a(i), remember):
select(y -> isprime(sqrt(6*y^2+10)-3), map(g, [$1..100]));
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|