A085244 Permanent of the symmetric n X n matrix M defined by M(i,j) = gcd(i,j) for 1 <= i,j <= n.

1, 3, 14, 112, 872, 14372, 154480, 3098480, 59710816, 1688186176, 27925409152, 1327833590272, 25675495200768, 1017195720916224, 47444016840290304, 2267031138313024512, 56480432945454004224, 4051971981329937580032

Offset: 1

Author

Yuval Dekel (dekelyuval(AT)hotmail.com), Aug 11 2003

Keywords

• nonn

Links

• Herman Jamke (hermanjamke(AT)fastmail.fm), May 13 2007, Table of n, a(n) for n = 1..23

Crossrefs

Cf. A001088, A005326.

Programs

PARI

permRWNb(a)=n=matsize(a)[1];if(n==1,return(a[1,1]));sg=1;in=vectorv(n);x=in;x=a[,n]-sum(j=1,n,a[,j])/2;p=prod(i=1,n,x[i]);for(k=1,2^(n-1)-1,sg=-sg;j=valuation(k,2)+1;z=1-2*in[j];in[j]+=z;x+=z*a[,j];p+=prod(i=1,n,x[i],sg));return(2*(2*(n%2)-1)*p) for(n=1,26,a=matrix(n,n,i,j,gcd(i,j));print1(permRWNb(a)",")) - Herman Jamke (hermanjamke(AT)fastmail.fm), May 13 2007

Extensions

More terms from Vladeta Jovovic, Aug 13 2003