a(n) is the number of ways prime(n) is a sum of two composite numbers r,s satisfying r < s.

Terms

a(0) =0a(1) =0a(2) =0a(3) =0a(4) =0a(5) =1a(6) =1a(7) =2a(8) =2a(9) =4a(10) =5a(11) =6a(12) =7a(13) =8a(14) =8a(15) =10a(16) =12a(17) =13a(18) =14a(19) =15a(20) =16a(21) =17a(22) =18a(23) =20a(24) =23a(25) =24a(26) =25a(27) =25a(28) =26a(29) =26