This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A352857 #22 Apr 09 2022 06:10:58
%S A352857 1,1,1,3,3,11,61,601,601,2881,20867,286065,2821431,45564697,775615705,
%T A352857 16612433139,16612433139,116158938203,1150638257617,23090252128971,
%U A352857 299243344044281,6870621769276771,164016991433619495,5064921427930587339,86249855741531767869
%N 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.
%e A352857 For n = 5:
%e A352857 - we have the following permutations (shown in decimal and in binary):
%e A352857 p\k 1 2 3 4 5 | 1 10 11 100 101
%e A352857 --- ----------------+------------------------
%e A352857 p1 5 3 2 4 1 | 101 11 10 100 1
%e A352857 p2 5 2 3 4 1 | 101 10 11 100 1
%e A352857 p3 3 2 5 4 1 | 11 10 101 100 1
%e A352857 p4 5 2 1 4 3 | 101 10 1 100 11
%e A352857 p5 1 2 5 4 3 | 1 10 101 100 11
%e A352857 p6 3 2 1 5 4 | 11 10 1 101 100
%e A352857 p7 1 3 2 5 4 | 1 11 10 101 100
%e A352857 p8 1 2 3 5 4 | 1 10 11 101 100
%e A352857 p9 3 2 1 4 5 | 11 10 1 100 101
%e A352857 p10 1 3 2 4 5 | 1 11 10 100 101
%e A352857 p11 1 2 3 4 5 | 1 10 11 100 101
%e A352857 - so a(5) = 11.
%o A352857 (PARI) a(n) = matpermanent(matrix(n, n, i,j, bitand(i,j)>0))
%Y A352857 Cf. A351722.
%K A352857 nonn,base
%O A352857 0,4
%A A352857 _Rémy Sigrist_, Apr 06 2022