John, Michael and I went to a funeral on Friday – this was for our colleague Alan Woods who died totally unexpectedly last week.

We were not especially close to Alan, who was a logician and number theorist, but he came to all of the Groups, Combinatorics and Computation seminars, often asking questions, and in fact he gave the seminar just a few weeks ago. He came along to the after-seminar lunches and the various Maths department functions etc. but I don’t think we ever spoke much about his life outside mathematics.

Perhaps sadly (or perhaps inevitably), I learned much more about him at the funeral than I ever knew before. The service was very moving and his sister and two children gave really lovely speeches describing his other lives as a devoted father, nature-lover, bush-walker, free thinker and record-breaking amateur radio enthusiast.  He was only 58 which makes him, if not exactly a contemporary of mine, at least not a million miles off, which is a rather sobering thought. The funeral was at Karrakatta cemetery on a spectacular Perth day of brilliant light and totally blue skies, but not yet with the dusty dryness and searing heat of full summer. His plot was under a shady tree and, as the celebrant said,  you couldn’t imagine a better time or place to lay to rest a dedicated nature lover.

Mathematically, his name is attached to at least one concept – the Erdős–Woods numbers are the integers numbers $k$ such that there is a closed interval of integers $[a, a+k]$ with the property that every integer in the interval has a factor in common with either $a$ or $a+k$. According to OEIS A059756, the smallest Erdős–Woods number is $16$ with associated interval $[2184, 2200]$.