a(n) is the total number of partitions of [1, 2, ..., k] into exactly n blocks, each of size 1, 2 or 3, for 0 <= k <= 3n.

A144416

a(n) is the total number of partitions of [1, 2, ..., k] into exactly n blocks, each of size 1, 2 or 3, for 0 <= k <= 3n.

Terms

    a(0) =1a(1) =3a(2) =31a(3) =842a(4) =45296a(5) =4061871a(6) =546809243a(7) =103123135501

External references