proposition: Lemma coef_odd_poly p i : (odd_poly p)`_i = p`_i.*2.+1.
proof: Proof. by rewrite coef_poly gtn_half_double if_nth ?leqVgt. Qed.
imports: HB(structures) mathcomp(ssreflect ssrbool ssrfun eqtype ssrnat seq choice) mathcomp(fintype bigop finset tuple) mathcomp(div ssralg countalg binomial)