COMBINATORICS
1999
14 years 1 months ago
1999
We show that if P(x) is a polynomial with nondecreasing, nonnegative coefficients, then the coefficient sequence of P(x + 1) is unimodal. Applications are given.
TCS
2008
14 years 2 months ago
2008
Soittola's theorem characterizes R+- or N-rational formal power series in one variable among the rational formal power series with nonnegative coefficients. We present here a...