Number of even cycles in range [A014137(n-1)..A014138(n-1)] of permutation A057505/A057506, with no fixed points of either A057163 or A057164.

A081157

Number of even cycles in range [A014137(n-1)..A014138(n-1)] of permutation A057505/A057506, with no fixed points of either A057163 or A057164.

Terms

    a(0) =0a(1) =0a(2) =0a(3) =0a(4) =0a(5) =2a(6) =8a(7) =20a(8) =60a(9) =148a(10) =402a(11) =986a(12) =2474a(13) =5918a(14) =14496a(15) =34708a(16) =84282a(17) =202664a(18) =492048

External references