x_1, x_2, x_3, x_4, x_5, x_6, x_7, 
3*x_1^2-3
18*x_1^3*x_4+6*x_1*x_4+9
1080*x_1^5*x_5+1080*x_1^2*x_4^2+120*x_1*x_5-81
45360*x_1^7*x_6+75600*x_1^4*x_4*x_5+15120*x_1^2*x_4*x_5+15120*x_1*x_4^3+1680*x_1*x_6+243
1088640*x_1^9*x_7+2540160*x_1^6*x_4*x_6+604800*x_1^4*x_5^2+1209600*x_1^3*x_4^2*x_5+120960*x_1^2*x_4*x_6+241920*x_1*x_4^2*x_5+40320*x_4^4+13440*x_1*x_7-243
359251200*x_1^11*x_2+1077753600*x_1^8*x_4*x_7+279417600*x_1^6*x_5*x_6+838252800*x_1^5*x_4^2*x_6+66528000*x_1^4*x_5*x_6+266112000*x_1^3*x_4*x_5^2+133056000*x_1^2*x_4^3*x_5+13305600*x_1^2*x_4*x_7+26611200*x_1*x_4^2*x_6+13305600*x_1*x_4*x_5^2+13305600*x_4^3*x_5+1478400*x_1*x_2+2187
56043187200*x_1^13*x_3+205491686400*x_1^10*x_2*x_4+56043187200*x_1^8*x_5*x_7+224172748800*x_1^7*x_4^2*x_7+14529715200*x_1^6*x_6^2+87178291200*x_1^5*x_4*x_5*x_6+72648576000*x_1^4*x_4^3*x_6+3459456000*x_1^4*x_5*x_7+13837824000*x_1^3*x_4*x_5*x_6+6918912000*x_1^3*x_5^3+20756736000*x_1^2*x_4^2*x_5^2+3459456000*x_1*x_4^4*x_5+691891200*x_1^2*x_2*x_4+1383782400*x_1*x_4^2*x_7+1383782400*x_1*x_4*x_5*x_6+691891200*x_4^3*x_6+691891200*x_4^2*x_5^2+76876800*x_1*x_3-6561
