%I
%S 6,0,8,144,80,384,2816,15360,125184,5322240,22966272,36771840,
%T 887224320,1488936960,217760382976,1484266291200,45948014198784,
%U 65021593190400,3267216288645120,856122753024000,3180322010587725824
%N a(n) = permanent of a bordered n X n (1,1)matrix with the following property: the elements on the border are 1; if we concatenate the rows of the matrix to form a vector v of length n^2, v_i = 1 if i is not a prime. The border of a matrix consists of the first and the last row and the first and the last column.
%H Simone Severini, <a href="http://wwwusers.york.ac.uk/~ss54">wwwusers.york.ac.uk/~ss54</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^(n1)1,sg=sg;j=valuation(k,2)+1;z=12*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=1,23,a=matrix(n,n,i,j,if(i==1j==1i==nj==n,1,1+2*isprime((i1)*n+j)));print1(permRWNb(a)","))  Herman Jamke (hermanjamke(AT)fastmail.fm), May 15 2007
%K sign
%O 3,1
%A _Simone Severini_, Feb 15 2006
%E More terms (and corrected definition) from Herman Jamke (hermanjamke(AT)fastmail.fm), May 15 2007
