Number of vertices at distance 2 from a given vertex in the n-Keller graph.

Terms

a(0) =0a(1) =10a(2) =29a(3) =84a(4) =247a(5) =734a(6) =2193a(7) =6568a(8) =19691a(9) =59058a(10) =177157a(11) =531452a(12) =1594335a(13) =4782982a(14) =14348921a(15) =43046736a(16) =129140179a(17) =387420506a(18) =1162261485a(19) =3486784420a(20) =10460353223a(21) =31381059630a(22) =94143178849a(23) =282429536504a(24) =847288609467