Number of dumbbells in all possible arrangements of dumbbells on a 2 X n rectangular array of compartments.

A123518

Number of dumbbells in all possible arrangements of dumbbells on a 2 X n rectangular array of compartments.

Terms

    a(0) =1a(1) =8a(2) =38a(3) =166a(4) =671a(5) =2602a(6) =9792a(7) =36068a(8) =130697a(9) =467556a(10) =1655406a(11) =5811290a(12) =20255279a(13) =70172502a(14) =241839184a(15) =829685064a(16) =2835099649a(17) =9653650752a(18) =32768012102a(19) =110913651342a(20) =374469646511

External references