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

1,2

Links

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

Prog

(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

Crossrefs

Cf. A001088, A005326.

Sequence in context: A258298 A121951 A276751 * A265001 A279429 A333797

Adjacent sequences: A085241 A085242 A085243 * A085245 A085246 A085247

Keyword

nonn

Author

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

Extensions

More terms from Vladeta Jovovic, Aug 13 2003

Status

approved