Number of n-permutations that have exactly two square roots.

A214854

Number of n-permutations that have exactly two square roots.

Terms

    a(0) =0a(1) =0a(2) =1a(3) =0a(4) =3a(5) =35a(6) =0a(7) =714a(8) =2835a(9) =35307a(10) =236880a(11) =3342350a(12) =28879158a(13) =461911086a(14) =4916519608a(15) =87798024300

External references