The sum of the entries in the top rows of 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.
A181292
The sum of the entries in the top rows of 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) =1a(2) =7a(3) =36a(4) =164a(5) =700a(6) =2868a(7) =11424a(8) =44576a(9) =171216a(10) =649520a(11) =2439360a(12) =9085632a(13) =33605312a(14) =123561536a(15) =451998720a(16) =1646101504a(17) =5971400960a(18) =21586910976a(19) =77796897792a(20) =279594972160
External references
- oeis: A181292