Number of n X n symmetric (0,1)-matrices with exactly n+1 entries equal to 1 and no zero rows or columns.
A135593
Number of n X n symmetric (0,1)-matrices with exactly n+1 entries equal to 1 and no zero rows or columns.
Terms
- a(0) =2a(1) =9a(2) =36a(3) =140a(4) =540a(5) =2142a(6) =8624a(7) =35856a(8) =152280a(9) =666380a(10) =2982672a(11) =13716144a(12) =64487696a(13) =310693320a(14) =1528801920a(15) =7691652992a(16) =39474925344a(17) =206758346256
External references
- oeis: A135593