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 A085244 Permanent of the symmetric n X n matrix M defined by M(i,j) = gcd(i,j) for 1 <= i,j <= n. 2

%I #6 May 10 2013 12:45:13

%S 1,3,14,112,872,14372,154480,3098480,59710816,1688186176,27925409152,

%T 1327833590272,25675495200768,1017195720916224,47444016840290304,

%U 2267031138313024512,56480432945454004224,4051971981329937580032

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

%H Herman Jamke (hermanjamke(AT)fastmail.fm), May 13 2007, <a href="/A085244/b085244.txt">Table of n, a(n) for n = 1..23</a>

%o (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

%Y Cf. A001088, A005326.

%K nonn

%O 1,2

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

%E More terms from _Vladeta Jovovic_, Aug 13 2003

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Last modified November 30 23:40 EST 2023. Contains 367464 sequences. (Running on oeis4.)