One-fourth of partial sums of A153976.

Terms

a(0) =2a(1) =9a(2) =27a(3) =65a(4) =135a(5) =252a(6) =434a(7) =702a(8) =1080a(9) =1595a(10) =2277a(11) =3159a(12) =4277a(13) =5670a(14) =7380a(15) =9452a(16) =11934a(17) =14877a(18) =18335a(19) =22365a(20) =27027a(21) =32384a(22) =38502a(23) =45450a(24) =53300a(25) =62127a(26) =72009a(27) =83027a(28) =95265a(29) =108810