Apply partial sum operator thrice to primes.

Terms

a(0) =2a(1) =9a(2) =26a(3) =60a(4) =122a(5) =225a(6) =386a(7) =624a(8) =962a(9) =1429a(10) =2056a(11) =2880a(12) =3942a(13) =5285a(14) =6956a(15) =9008a(16) =11500a(17) =14493a(18) =18054a(19) =22254a(20) =27166a(21) =32869a(22) =39446a(23) =46986a(24) =55586a(25) =65347a(26) =76372a(27) =88768a(28) =102644a(29) =118113