a(n) = n-th prime prime(n) subtracted from sum of all composites between prime(n) and prime(n-1).

Terms

a(0) =-3a(1) =-1a(2) =-1a(3) =16a(4) =-1a(5) =28a(6) =-1a(7) =40a(8) =101a(9) =-1a(10) =133a(11) =76a(12) =-1a(13) =88a(14) =197a(15) =221a(16) =-1a(17) =253a(18) =136a(19) =-1a(20) =301a(21) =160a(22) =341a(23) =554a(24) =196a(25) =-1a(26) =208a(27) =-1a(28) =220a(29) =1433