p(p(2^n)-p(n+1)+p(n*2)-p(n^2))-1, where p(n)=n-th prime.

Terms

a(0) =1a(1) =2a(2) =2a(3) =18a(4) =228a(5) =1068a(6) =3696a(7) =11046a(8) =30390a(9) =77976a(10) =190978a(11) =455166a(12) =1063452a(13) =2445450a(14) =5561658a(15) =12522478a(16) =27987780a(17) =62097646a(18) =136990768a(19) =300684322