Number of cycles with 2 alternating runs in all permutations of [n] (it is assumed that the smallest element of the cycle is in the first position).

A187246

Number of cycles with 2 alternating runs in all permutations of [n] (it is assumed that the smallest element of the cycle is in the first position).

Terms

    a(0) =0a(1) =0a(2) =0a(3) =1a(4) =7a(5) =42a(6) =267a(7) =1900a(8) =15263a(9) =137494a(10) =1375195a(11) =15127656a(12) =181532895a(13) =2359929682a(14) =33039019643a(15) =495585302836

External references