Partial sums of A100381.

Terms

a(0) =0a(1) =4a(2) =28a(3) =124a(4) =444a(5) =1404a(6) =4092a(7) =11260a(8) =29692a(9) =75772a(10) =188412a(11) =458748a(12) =1097724a(13) =2588668a(14) =6029308a(15) =13893628a(16) =31719420a(17) =71827452a(18) =161480700a(19) =360710140a(20) =801112060a(21) =1769996284a(22) =3892314108a(23) =8522825724a(24) =18589155324a(25) =40399536124a(26) =87509958652