Number of columns with an even sum in all 2-compositions of n. 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.
A181328
Number of columns with an even sum in all 2-compositions of n. 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) =0a(1) =0a(2) =3a(3) =12a(4) =59a(5) =248a(6) =1024a(7) =4080a(8) =15948a(9) =61312a(10) =232792a(11) =874864a(12) =3260360a(13) =12064928a(14) =44378984a(15) =162399504a(16) =591613880a(17) =2146724864a(18) =7762397576a(19) =27980907248a(20) =100580448920a(21) =360636908000
External references
- oeis: A181328