Divide even numbers into groups with prime(n) elements and add together.

Terms

a(0) =2a(1) =18a(2) =70a(3) =182a(4) =484a(5) =884a(6) =1666a(7) =2546a(8) =4048a(9) =6612a(10) =8928a(11) =13172a(12) =17794a(13) =22274a(14) =28576a(15) =37524a(16) =48380a(17) =57340a(18) =71556a(19) =85626a(20) =98550a(21) =118658a(22) =138112a(23) =163404a(24) =196134a(25) =224220a(26) =249672a(27) =281838a(28) =310650a(29) =347136