June 8, 2014

ISA: An Integer Sequence Analyzer

ISA is a proof of concept of an integer sequence analyzer. It consists of a very simple web interface for entering the beginning of an integer sequence. When clicking on Analyze, ISA tries to compute a formula for an infinite sequence that starts with the entered numbers.
Under the hood, ISA uses a term generator to compute (recursive) formulas. These formulas are evaluated and the result is compared with the sequence entered by the user. If no matching formula was found after 30 seconds ISA gives up and times out. To get a feeling what is currently possible, try out the following sequences:

  • 0 0 1 1 4 4 9 9
  • 2 3 6 18 108
  • 1 2 2 3 3 3

The interface and the idea of ISA resembles OEIS which was created by Neil Sloane (former researcher at AT&T Labs). The main difference is that OEIS is a database, whereas ISA is a formula generator.

Since I am using a Raspberry Pi to host and run ISA, some heuristics might be useful to find common sequences more directly. But of course, in general only a tiny class of sequences can be automatically found in this way.