67207073domain: NPropertiesPrimalityPrimeyesAppears in sequencesLower (1/2)-midsequence of (2^n) and F(n), where F = A000045 (Fibonacci numbers); see Comments.at n=27A390559Upper (1/2)-midsequence of (2^n) and F(n), where F = A000045 (Fibonacci numbers); see Comments.at n=27A390560Prime numbersat n=3963249