Number of partitions of {1...n} containing 2 detached pairs of consecutive integers, i.e., partitions in which only 1- or 2-strings of consecutive integers can appear in a block and there are exactly two 2-strings.

A105488

Number of partitions of {1...n} containing 2 detached pairs of consecutive integers, i.e., partitions in which only 1- or 2-strings of consecutive integers can appear in a block and there are exactly two 2-strings.

Terms

    a(0) =1a(1) =6a(2) =30a(3) =150a(4) =780a(5) =4263a(6) =24556a(7) =149040a(8) =951615a(9) =6378625a(10) =44785620a(11) =328660566a(12) =2515643767a(13) =20044428810a(14) =165955025400

External references