MathDB
2022 Putnam B1

Source:

December 4, 2022
PutnamPutnam 2022

Problem Statement

Suppose that P(x)=a1x+a2x2++anxnP(x)=a_1x+a_2x^2+\ldots+a_nx^n is a polynomial with integer coefficients, with a1a_1 odd. Suppose that eP(x)=b0+b1x+b2x2+e^{P(x)}=b_0+b_1x+b_2x^2+\ldots for all x.x. Prove that bkb_k is nonzero for all k0.k \geq 0.