Sum of the numbers between k := n-th nonprime and 2k (like a jump in a Sieve of Eratosthenes).

Terms

a(0) =0a(1) =18a(2) =45a(3) =84a(4) =108a(5) =135a(6) =198a(7) =273a(8) =315a(9) =360a(10) =459a(11) =570a(12) =630a(13) =693a(14) =828a(15) =900a(16) =975a(17) =1053a(18) =1134a(19) =1305a(20) =1488a(21) =1584a(22) =1683a(23) =1785a(24) =1890a(25) =2109a(26) =2223a(27) =2340a(28) =2583a(29) =2838