Some Math Stuff

• Conjecture + Proof = Theorem - a presentation about mathematical conjectures, proofs and theorems. I gave this presentation multiple times to the 5th grade honors math classes in Holmdel.
• The Difficulty of Fixing Python Indentation Errors - an article that examines the difficulty of fixing indentation errors in Python programs. We prove that the problem is NP-hard.
• The difficulty of schema conformance problems - an in-depth article that examines the difficulty of the schema conformance problem for multiple XML schema languages.
  • The Undecidability of the Schematron Conformance Problem - an earlier article that examines the undecidability of the Schematron conformance problem.
• Some integer sequences that I contributed to the On-Line Encyclopedia of Integer Sequences (OEIS):
  • https://oeis.org/A399884 - Variant of the Busy Beaver sequence for the Post correspondence problem. I co-authored this noncomputable sequence with my son Clark R. Lyons.
  • https://oeis.org/A235383 - Fibonacci numbers that are the product of other Fibonacci numbers. This sequence was one of the three winners of the 2014 OEIS contest for best new integer sequence.
  • https://oeis.org/A253426 - Reusable Paper Tape Numbers: Maximum number of symbols that can be encoded on an n-hole paper tape, such that a used paper tape can always be reused at least once.
  • https://oeis.org/A296818 - Squarefree values of n for which the quadratic field Q[ sqrt(n) ] possesses a norm-Euclidean ideal class. Based on the research of Kelly Emmrich and Clark R. Lyons.
  • https://oeis.org/A219696 - Numbers k such that the trajectory of 3k + 1 under the '3x + 1' map reaches k.