178956973domain: NAppears in sequencesa(n) = (7 - 4*(-2)^n)/3.at n=27A083594Jacobsthal numbers A001045 incremented by 2.at n=29A153643First differences of A135351.at n=31A155980a(n) = (2*2^n+7*(-1)^n)/3.at n=28A171382a(n) = (2*4^n + 7)/3.at n=14A321358