isabelle/valid/mathd_numbertheory_109.thy (12 lines of code) (raw):
(*
Authors: Wenda Li
*)
theory mathd_numbertheory_109
imports Complex_Main "HOL-Computational_Algebra.Computational_Algebra"
begin
theorem mathd_numbertheory_109:
fixes v :: "nat \<Rightarrow> nat"
assumes "\<forall> n. v n = 2 * n - 1"
shows "(\<Sum> k \<in>{1..<101}. v k) mod 7 = 4"
sorry
end