MathDB
Polynomial

Source: 2005 National High School Mathematics League, Exam One, Problem 7

March 19, 2020
algebrapolynomial

Problem Statement

The polynomial f(x)=1x+x2x3+x19+x20f(x)=1-x+x^2-x^3+\cdots-x^{19}+x^{20} is written into the form g(y)=a0+a1y+a2y2++a20y20g(y)=a_0+a_1y+a_2y^2+\cdots+a_{20}y^{20}, where y=x4y=x-4, then a0+a1++a20=a_0+a_1+\cdots+a_{20}=________.