OFFSET
1,1
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 1..600
EXAMPLE
Twin primes (3,5) are in this sequence because 3+5+1=9 and 3*5+1=16; (11,13) because 11+13+1=25 and 11*13+1=144.
MATHEMATICA
tppQ[{a_, b_}]:=IntegerQ[Sqrt[a+b+1]]&&IntegerQ[ Sqrt[a b +1]]; Flatten[Select[ Select[Partition[ Prime[Range[9000]], 2, 1], Last[#]-First[#]==2&], tppQ]] (* Harvey P. Dale, Apr 01 2011 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Vincenzo Librandi, Oct 25 2009
EXTENSIONS
Corrected and extended by Harvey P. Dale, Apr 01 2011.
STATUS
approved