Pell Explorer

Step 1 / 7
5 terms shown
Step 1
Loading…
START WITH ANY TWO NUMBERS:
, then each term = 2·(prev) + (prev-prev)
↑ Type any numbers you like and watch the sequence change.
💡 Try this: Click + Add a term to grow the sequence. Drag any circle to rearrange. Open the Number Workshop when you're ready to hunt for hidden patterns.

Number Workshop

Some of these columns secretly equal each other. Which ones? And do any of them stay tiny while others explode?
No formulas, no answers. Just numbers. Add a term to extend the table.

Terms

small
large

Partial Sum & Visual Proof

Silver Ratio Convergence

💬 PellGPT
PellGPT needs an API key to chat. Free Groq keys work great (start with gsk_) — get one at console.groq.com. OpenRouter and DeepSeek keys also work.