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 A349099 #19 Mar 27 2022 16:46:14 %S A349099 1,1,5,32,1074,12600,1525292,34078720,4072850100,263459065600, %T A349099 106809546673488,2254519427530752,3172225081523720416, %U A349099 210351382651302645760,45654014718074873700000,11122845097194072534155264,18156837198112938091803999360,795289872611524024920215715840 %N A349099 a(n) is the permanent of the n X n matrix M(n) defined as M(n)[i,j] = i*j (mod n + 1). %C A349099 Det(M(n)) = 0 iff n = 4 or n > 5. %C A349099 Rank(M(n)) = A088922(n+1). %C A349099 Tr(M(n)) = A048153(n+1). %e A349099 See A352620 for the examples of matrix M(n). %p A349099 a:= n-> `if`(n=0, 1, LinearAlgebra[Permanent]( %p A349099 Matrix(n, (i, j)-> (i*j) mod (n+1)))): %p A349099 seq(a(n), n=0..16); # _Alois P. Heinz_, Mar 25 2022 %t A349099 Join[{1},Table[Permanent[Table[Mod[j*Table[i, {i, n}], n+1], {j, n}]], {n, 17}]] %o A349099 (PARI) a(n) = matpermanent(matrix(n,n,i,j,(i*j)%(n+1))); \\ _Michel Marcus_, Mar 26 2022 %Y A349099 Cf. A352620. %Y A349099 Cf. A048153, A074930, A088922, A160255. %K A349099 nonn %O A349099 0,3 %A A349099 _Stefano Spezia_, Mar 25 2022