The number of even entries in all the 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.
A181298
The number of even entries in all the 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) =2a(2) =12a(3) =56a(4) =246a(5) =1024a(6) =4128a(7) =16248a(8) =62832a(9) =239640a(10) =903944a(11) =3379064a(12) =12536552a(13) =46215672a(14) =169443592a(15) =618303864a(16) =2246863624a(17) =8135066488a(18) =29358346888a(19) =105642047864a(20) =379143054472
External references
- oeis: A181298