/- Copyright 2026 The Formal Conjectures Authors. Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at https://www.apache.org/licenses/LICENSE-2.0 Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License. -/ import FormalConjecturesUtil namespace FlintCooksonHills

The Flint Hills series summing $csc(n)^2 / n^3$ from $n=1$ to $\infty$ converges. (Note that we 0-index the series below.)

@[category research open, AMS 40] theorem declaration uses 'sorry'flint_hills_series_converges : answer(sorry) Summable (fun n : => 1 / ((((n + 1) : )^3) * (Real.sin (n + 1)^2))) := True Summable fun n => 1 / ((n + 1) ^ 3 * Real.sin (n + 1) ^ 2) All goals completed! 🐙

The Cookson Hills series summing $sec(n)^2 / n^3$ from $n=1$ to $\infty$ converges.

@[category research open, AMS 40] theorem declaration uses 'sorry'cookson_hills_series_converges : answer(sorry) Summable (fun n : => 1 / ((((n + 1) : )^3) * (Real.cos (n + 1)^2))) := True Summable fun n => 1 / ((n + 1) ^ 3 * Real.cos (n + 1) ^ 2) All goals completed! 🐙 end FlintCooksonHills