login
A174917
Lesser of twin primes p1 such that p2+(p2^2-p1^2) is a prime number.
5
5, 11, 29, 41, 107, 137, 149, 197, 239, 347, 431, 461, 569, 599, 659, 809, 821, 1019, 1229, 1289, 1481, 1619, 1787, 1877, 1931, 2027, 2129, 2141, 2309, 2339, 2657, 2687, 2801, 2969, 3119, 3329, 3467, 3557, 3581, 4001, 4019, 4127, 4241, 4421, 4547, 4649
OFFSET
1,1
COMMENTS
5+(7^2-5^2)=5+24=29,...
LINKS
MATHEMATICA
lst={}; Do[p1=Prime[n]; p2=p1+2; If[PrimeQ[p2]&&PrimeQ[p2+(p2^2-p1^2)], AppendTo[lst, p1]], {n, 4*6!}]; lst
Select[Partition[Prime[Range[700]], 2, 1], #[[2]]-#[[1]]==2&& PrimeQ[ #[[2]]+ #[[2]]^2-#[[1]]^2]&][[All, 1]] (* Harvey P. Dale, Dec 18 2021 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
STATUS
approved