a(n) is the number of permutations p of {1, 2, ..., n} such that for any k in 1..n, k and p(k) share a common 1-bit.

A352857

a(n) is the number of permutations p of {1, 2, ..., n} such that for any k in 1..n, k and p(k) share a common 1-bit.

Terms

    a(0) =1a(1) =1a(2) =1a(3) =3a(4) =3a(5) =11a(6) =61a(7) =601a(8) =601a(9) =2881a(10) =20867a(11) =286065a(12) =2821431a(13) =45564697a(14) =775615705a(15) =16612433139a(16) =16612433139a(17) =116158938203

External references