A002326((k-1)/2) for composite numbers k from A141229.

Terms

a(0) =18a(1) =100a(2) =1210a(3) =2028a(4) =6498a(5) =23548a(6) =49284a(7) =146068a(8) =201898a(9) =223260a(10) =296274a(11) =564898a(12) =1020100a(13) =1213594a(14) =2230930a(15) =2666298a(16) =3285748a(17) =4304178a(18) =5147788a(19) =5703298a(20) =5896980a(21) =7606564a(22) =9349410a(23) =11645554a(24) =19392748a(25) =25067908a(26) =31754524a(27) =41661514a(28) =42386748a(29) =51755988