Number of nodes in graph BC(n,2) when the internal nodes are counted with multiplicity.

Terms

a(0) =3a(1) =15a(2) =58a(3) =156a(4) =339a(5) =643a(6) =1110a(7) =1788a(8) =2731a(9) =3999a(10) =5658a(11) =7780a(12) =10443a(13) =13731a(14) =17734a(15) =22548a(16) =28275a(17) =35023a(18) =42906a(19) =52044a(20) =62563a(21) =74595a(22) =88278a(23) =103756a(24) =121179a(25) =140703a(26) =162490a(27) =186708a(28) =213531a(29) =243139