OFFSET
1,1
COMMENTS
Primes in A184417.
Obviously, no prime has the form q^2+(q+2)^2+1, where q and q+2 are twin primes.
LINKS
Bruno Berselli, Table of n, a(n) for n = 1..1000
EXAMPLE
3529 (prime) is in the sequence because 3529+1 = 41^2+43^2, where 41 and 43 are twin primes.
MAPLE
A224505:=proc(q) local a, n;
for n from 1 to q do
if ithprime(n+1)-ithprime(n)=2 then a:=ithprime(n+1)^2+ithprime(n)^2-1;
if isprime(a) then print(a); fi; fi;
od; end: A224505(10^6); # Paolo P. Lava, Apr 17 2013
MATHEMATICA
Select[(#[[1]]^2 + #[[2]]^2 - 1) & /@ Select[Partition[Prime[Range[700]], 2, 1], #[[2]] - #[[1]] == 2 &], PrimeQ]
PROG
(Magma) [p: r in PrimesUpTo(5000) | IsPrime(r+2) and IsPrime(p) where p is 2*r^2+4*r+3];
CROSSREFS
KEYWORD
nonn
AUTHOR
Bruno Berselli, Apr 08 2013
STATUS
approved