Number of ordered pairs of complementary subsets of an n-set with both subsets of cardinality at least 2.

A052515

Number of ordered pairs of complementary subsets of an n-set with both subsets of cardinality at least 2.

Terms

    a(0) =0a(1) =0a(2) =0a(3) =0a(4) =6a(5) =20a(6) =50a(7) =112a(8) =238a(9) =492a(10) =1002a(11) =2024a(12) =4070a(13) =8164a(14) =16354a(15) =32736a(16) =65502a(17) =131036a(18) =262106a(19) =524248a(20) =1048534a(21) =2097108a(22) =4194258a(23) =8388560a(24) =16777166a(25) =33554380a(26) =67108810a(27) =134217672a(28) =268435398a(29) =536870852

External references