permcount[v_]:=模块[{m=1,s=0,t,i,k=0},对于[i=1,i<=长度[v],i++,t=v[i]];k=如果[i>1&&t==v[[i-1]],k+1,1];m*=t*k;s+=t];s/m] ;
边[v_]:=和[2*GCD[v[i]],v[[j]]],{i,2,长度[v]},{j,1,i-1}]+和[v[[i]]-1,{i;
a[n_]:=模块[{s=0},如果[n==0,返回[1];求和[Do[s+=permcount[p]*2^edges[p]*系数[Product[1-x^p[[i]],{i,1,Length[p]}],x,n-k]/k!,{p,整数分区[k]}],{k,1,n}];s] ;