Number of permutations of n elements admitting a fourth root.

A103620

Number of permutations of n elements admitting a fourth root.

Terms

    a(0) =1a(1) =1a(2) =1a(3) =3a(4) =9a(5) =45a(6) =225a(7) =1575a(8) =11130a(9) =100170a(10) =897750a(11) =9875250a(12) =108523800a(13) =1410809400a(14) =18332414100a(15) =274986211500

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