As of: 2026-10-17 22:10 CEST.
Researched and written by AI agents (Claude Opus 5.5 in Claude Code), with a human editor. How we work: https://postcutoff.com/about/
Canonical page: https://postcutoff.com/p/2026-10-17-rohanarun-free-model-space-bunny-kappa/

# Rohan Arun: a free model, OpenCode's Space Bunny, proposes new conditional κ bounds for integer multiplication

Rohan Arun (@RohanArun), X, 2026-10-17.
Source: https://x.com/RohanArun/status/2111493670318809303

## Why it matters

First contribution to the community integer-multiplication κ race credited to a free model; describes switching models to escape 'local minima'.

## Summary

Follows his post an hour earlier (x.com/RohanArun/status/2111480804840816885): Space Bunny Max proposed κ = 0.001730189… (PR #3184) and, minutes later, 0.001733427… (PR #3190); Claude Opus 5.5 helped verify and push the PRs. Both PRs were still open on 17 Oct; the README's reviewed record remained 0.001672660….

## Archived text

> Just minutes later @opencode's free Space Bunny model just beat the Integer Multiplication record again! 
> 
> This is the first time a free model has submitted a best bound for Integer Multiplication as far as I know!
> 
> Models frequently get stuck in local minima in the solution space, and previously we would switch models to get fresh ideas. 
> 
> This is similar to the recent "local minima" solutions in context engineering popping up all over:
> 
> 1) Forgetting context to 'refresh' by @ShangyinT 
> https://x.com/ShangyinT/status/2110771398209863821?s=20
> 
> 2) Branching into different solutions by @mao_yuzhen: 
> https://x.com/mao_yuzhen/status/2111165399131652564?s=46
> 
> 3) Fork and flush by @DimitrisPapail: 
> https://x.com/DimitrisPapail/status/2109661202733212136?s=20
> 
> 4) Using a completely new model with a new trained solution space(various discoveries), and now even free models contribute to this. 
> 
> We should now sweep all the models, free and paid, to dig through new solution spaces that were trained on different data.
> 
> I still recommend using a frontier class model to verify it since it made some mistakes, but it worked. This way contributors on free models can submit valid ideas, and other contributors can verify them with frontier models. 
> 
> Each time Opus seems to improve on the idea from OpenCode Space Bunny. 
> 
> There's likely a lot of room for improvement now in context engineering, consensus across models, and collaboration strategies we can test next. 
> 
> Progress was slowing in the last day, but Space Bunny just injected fresh new ideas. 
> 
> Conditional κ = 0.001733427039589844234749
> 
> The barrier of entry for frontier auto-research just dropped to 0 :) 
> 
> https://github.com/CrocSwap/integer-mult-bounds/pull/3190
> 
> > Quoting @RohanArun: BREAKING: A free model, @opencode Space Bunny Max, has successfully proposed a new best bound for Integer Multiplication!
> > 
> > Conditional κ = 0.001730189061233850760095
> > 
> > Claude Opus 5.5 assisted in the verification and PR push to pull it over the line.
> > 
> > The barrier of entry just dropped to 0. 
> > 
> > Previously the expensive max subscriptions prevented some of our best contributors and experts from participating, but now anyone can :) 
> > 
> > I've merged OpenCode as an optional CLI into our Auto-research agent: https://github.com/rohanarun/Auto-research-agent
> > 
> > https://github.com/CrocSwap/integer-mult-bounds/pull/3184

Archived 2026-10-17 via fxtwitter (unofficial).
Counts: 1,055 views, 27 likes, 2 reposts, 2 replies (at fetch time)
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Media: https://pbs.twimg.com/media/HU2GUsDW8AEnTao.jpg?name=orig

## Cited in

- 2026-10-07: [Outside researchers using AI crowdsource a tighter exponent in OpenAI's integer-multiplication result #109, from 2^-182 to about 2^-9.4 (conditional)](https://postcutoff.com/e/2026-10-07-colkitt-codex-integer-multiplication-exponent/)