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A085244
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Permanent of the symmetric n X n matrix M defined by M(i,j) = gcd(i,j) for 1 <= i,j <= n.
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2
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1, 3, 14, 112, 872, 14372, 154480, 3098480, 59710816, 1688186176, 27925409152, 1327833590272, 25675495200768, 1017195720916224, 47444016840290304, 2267031138313024512, 56480432945454004224, 4051971981329937580032
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,2
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LINKS
| Herman Jamke (hermanjamke(AT)fastmail.fm), May 13 2007, Table of n, a(n) for n = 1..23
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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
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CROSSREFS
| Cf. A001088, A005326.
Sequence in context: A167017 A051106 A121951 * A180435 A007140 A122081
Adjacent sequences: A085241 A085242 A085243 * A085245 A085246 A085247
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KEYWORD
| nonn
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AUTHOR
| Yuval Dekel (dekelyuval(AT)hotmail.com), Aug 11 2003
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EXTENSIONS
| More terms from Vladeta Jovovic (vladeta(AT)eunet.rs), Aug 13 2003
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