a(n) is the number of configurations of n indistinguishable pairs placed on the vertices of the ladder graph P_2 X P_n such that all but 5 such pairs are joined by an edge.
A318270
a(n) is the number of configurations of n indistinguishable pairs placed on the vertices of the ladder graph P_2 X P_n such that all but 5 such pairs are joined by an edge.
Terms
- a(0) =0a(1) =0a(2) =0a(3) =0a(4) =0a(5) =186a(6) =3666a(7) =36714a(8) =253386a(9) =1369260a(10) =6209700a(11) =24668742a(12) =88338174a(13) =290968686a(14) =894709790a(15) =2597386330a(16) =7181246394a(17) =19040425628a(18) =48684375292a(19) =120592523460a(20) =290476059204a(21) =682548818802
External references
- oeis: A318270