Number of matchings in the wheel graph with n spokes.

Terms

a(0) =2a(1) =5a(2) =10a(3) =19a(4) =36a(5) =66a(6) =120a(7) =215a(8) =382a(9) =673a(10) =1178a(11) =2050a(12) =3550a(13) =6121a(14) =10514a(15) =17999a(16) =30720a(17) =52290a(18) =88788a(19) =150427a(20) =254342a(21) =429245a(22) =723190a(23) =1216514a(24) =2043386a(25) =3427661a(26) =5742490a(27) =9609355a(28) =16062492a(29) =26821698