p_{1}(x) = (x1)^{3 }+ 313(x1)^{2}  77(x1)  8
p_{2}(x) = (x3)^{3 }+ 313(x3)^{2}  77(x3)  8
p_{3}(x) = (x6)^{3 etc}
Oh it's just triangular numbers. The 20th is 210.
p_{20}(x) = (x210)^{3 }+ 313(x210)^{2}  77(x210)  8
The x coefficient would be
3*210^2 + 313*2*210  77 = 763

Posted by Jer
on 20151014 13:02:39 