A085905 Permanent of the symmetric n X n matrix M defined by M(i,j) = lcm(i,j) for 1 <= i,j <= n.

1, 6, 144, 5952, 772560, 73664640, 29745273600, 8715934402560, 5068085799813120, 2756328707949465600, 4581860819083475558400, 2696083278990328597708800, 7844679216026128507826995200

Offset

1,2

Links

Vaclav Kotesovec, Table of n, a(n) for n = 1..35

Example

a(2)=6 since the 2 by 2 matrix A with rows [1,2],[2,2] has permanent 1*2+2*2=6.

Maple

with(linalg): a:=(i, j)->lcm(i, j): seq(permanent(matrix(n, n, a)), n=1..14); # Emeric Deutsch, Feb 08 2005

Mathematica

a[n_] := Permanent[Table[LCM[i, j], {i, 1, n}, {j, 1, n}]]; Table[an = a[n]; Print["a(", n, ") = ", an]; an, {n, 1, 14}] (* Jean-François Alcover, Jan 07 2016 *)

Prog

(PARI) a(n)=matpermanent(matrix(n, n, r, c, lcm(r, c)));
vector(23, n, a(n)) \\ Joerg Arndt, Aug 15 2019

Crossrefs

Cf. A060238, A085244, A034444.

Sequence in context: A208230 A010043 A270504 * A203978 A090443 A379452

Adjacent sequences: A085902 A085903 A085904 * A085906 A085907 A085908

Keyword

nonn

Author

Yuval Dekel (dekelyuval(AT)hotmail.com), Aug 16 2003

Extensions

More terms from Emeric Deutsch, Feb 08 2005

Status

approved