Number of n X n binary arrays symmetric about both diagonal and antidiagonal with all ones connected only in a 1000-1110-0111 pattern in any orientation.
A146819
Number of n X n binary arrays symmetric about both diagonal and antidiagonal with all ones connected only in a 1000-1110-0111 pattern in any orientation.
Terms
- a(0) =1a(1) =1a(2) =1a(3) =1a(4) =1a(5) =1a(6) =1a(7) =3a(8) =9a(9) =19a(10) =39a(11) =117a(12) =351a(13) =957a(14) =3341a(15) =15997a(16) =83175a(17) =424759a(18) =2415699a(19) =15982837a(20) =113541201a(21) =873618675
External references
- oeis: A146819