Number of n X n symmetric matrices with (0,1) entries and all row sums 2.
A000986
Number of n X n symmetric matrices with (0,1) entries and all row sums 2.
Terms
- a(0) =1a(1) =0a(2) =1a(3) =4a(4) =18a(5) =112a(6) =820a(7) =6912a(8) =66178a(9) =708256a(10) =8372754a(11) =108306280a(12) =1521077404a(13) =23041655136a(14) =374385141832
External references
- oeis: A000986