1,3

(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) ndiv(n)=if(n>0, numdiv(n), 0) for(n=1, 23, a=matrix(n, n, i, j, ndiv(abs(i-j))); print1(permRWNb(a)", ")) - Herman Jamke (hermanjamke(AT)fastmail.fm), May 14 2007

Cf. A071084.

Sequence in context: A045787 A067474 A053769 this_sequence A055793 A121275 A029991

Adjacent sequences: A086091 A086092 A086093 this_sequence A086095 A086096 A086097

nonn

Yuval Dekel (dekelyuval(AT)hotmail.com), Aug 24 2003

More terms from Herman Jamke (hermanjamke(AT)fastmail.fm), May 14 2007