Number of n X n symmetric binary arrays with rows, considered as graycode numbers, in strictly increasing order, and no more than 2 ones in any row or column.
A162110
Number of n X n symmetric binary arrays with rows, considered as graycode numbers, in strictly increasing order, and no more than 2 ones in any row or column.
Terms
- a(0) =2a(1) =4a(2) =8a(3) =21a(4) =53a(5) =145a(6) =405a(7) =1180a(8) =3562a(9) =11030a(10) =35306a(11) =115338a(12) =387443a(13) =1326992a(14) =4650201a(15) =16604351a(16) =60443887a(17) =223971602a(18) =844095896a(19) =3234044019a(20) =12582749734a(21) =49703821584a(22) =199149007691a(23) =809153896365
External references
- oeis: A162110