The sum of the lengths of 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. The length of the 2-composition is the number of columns.
A181290
The sum of the lengths of 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. The length of the 2-composition is the number of columns.
Terms
- a(0) =0a(1) =2a(2) =11a(3) =52a(4) =227a(5) =944a(6) =3800a(7) =14944a(8) =57748a(9) =220128a(10) =829968a(11) =3101376a(12) =11502704a(13) =42393088a(14) =155392768a(15) =566918144a(16) =2059768384a(17) =7456496128a(18) =26905720576a(19) =96804463616a(20) =347386161920
External references
- oeis: A181290