Right edge of the triangle in A033291.

Terms

a(0) =1a(1) =4a(2) =12a(3) =28a(4) =50a(5) =84a(6) =133a(7) =192a(8) =270a(9) =370a(10) =484a(11) =624a(12) =793a(13) =980a(14) =1200a(15) =1456a(16) =1734a(17) =2052a(18) =2413a(19) =2800a(20) =3234a(21) =3718a(22) =4232a(23) =4800a(24) =5425a(25) =6084a(26) =6804a(27) =7588a(28) =8410a(29) =9300