Number of 2-compositions of n having no column with an even sum. A 2-composition of n is a nonnegative matrix with two rows, such that each column has at least one nonzero entry and whose entries sum up to n.
A181329
Number of 2-compositions of n having no column with an even sum. A 2-composition of n is a nonnegative matrix with two rows, such that each column has at least one nonzero entry and whose entries sum up to n.
Terms
- a(0) =1a(1) =2a(2) =4a(3) =12a(4) =32a(5) =86a(6) =232a(7) =624a(8) =1680a(9) =4522a(10) =12172a(11) =32764a(12) =88192a(13) =237390a(14) =638992a(15) =1720000a(16) =4629792a(17) =12462194a(18) =33544980a(19) =90294348a(20) =243048864a(21) =654224230a(22) =1761001208a(23) =4740156528a(24) =12759266608a(25) =34344622042a(26) =92446776092a(27) =248842639740a(28) =669819565056
External references
- oeis: A181329