Third column of A059450.

Terms

a(0) =0a(1) =0a(2) =5a(3) =17a(4) =50a(5) =136a(6) =352a(7) =880a(8) =2144a(9) =5120a(10) =12032a(11) =27904a(12) =64000a(13) =145408a(14) =327680a(15) =733184a(16) =1630208a(17) =3604480a(18) =7929856a(19) =17367040a(20) =37879808a(21) =82313216a(22) =178257920a(23) =384827392a(24) =828375040a(25) =1778384896a(26) =3808428032a(27) =8136949760a(28) =17347641344