Number of 6-cycles in the n-triangular graph.

Terms

a(0) =0a(1) =0a(2) =16a(3) =920a(4) =7800a(5) =36260a(6) =122080a(7) =334656a(8) =794640a(9) =1696200a(10) =3334320a(11) =6137560a(12) =10706696a(13) =17859660a(14) =28683200a(15) =44591680a(16) =67393440a(17) =99365136a(18) =143334480a(19) =202771800a(20) =281890840a(21) =385759220a(22) =520418976a(23) =693017600a(24) =911950000a(25) =1187011800a(26) =1529564400a(27) =1952712216a(28) =2471492520