漸化式ガチャ

The Recurrence Formula Gacha is a service released on the Oishii Mathematics website on July 21, 2020, that randomly presents three recurrence formula problems up to Mathematics IIB. It is an enhanced app version that inherits the functionality of the web version.
In addition to the web version, the app version has the following features:

① More questions than the web version, with 47,880 possible gacha combinations (18,620 in the web version)
② Unlimited gacha spins, no time limit
③ Advanced level only switch (you can set it to always get an advanced level with (5))
④ Additional information included (contains relevant information such as background knowledge and sources for the questions)
⑤ Built-in timer (measures up to 100 minutes after spinning the gacha, useful for time attacks)
⑥ New question identification function (distinguishes between new and previously released questions)
⑦ Marking function (allows you to mark questions you answered correctly)
⑧ No ads
⑨ Calculation sheet function (simple)
⑩ List of all questions from beginner to advanced (including questions added since the web version)

First-time users can try the free web version by searching "recurrence formula gacha" on Google and checking it out within Oishii Mathematics.
Please also search for "recurrence formula gacha" on X (Twitter).