A 2nd order recursion: a(1)=a(2)=1, a(n) = prime(a(n-2)) + pi(a(n-1)) = A000040(a(n-2)) + A000720(a(n-1)).

A082095

A 2nd order recursion: a(1)=a(2)=1, a(n) = prime(a(n-2)) + pi(a(n-1)) = A000040(a(n-2)) + A000720(a(n-1)).

Terms

    a(0) =1a(1) =1a(2) =2a(3) =3a(4) =5a(5) =8a(6) =15a(7) =25a(8) =56a(9) =113a(10) =293a(11) =679a(12) =2036a(13) =5389a(14) =18447a(15) =54920a(16) =211347a(17) =697252a(18) =2974827a(19) =10741681a(20) =50245401a(21) =196570892a(22) =998427899a(23) =4197026430a(24) =22963115248a(25) =103007695615a(26) =603032992418

External references