As mentioned previously, the Encyclopedia of Integer Sequences is 50 this year. To celebrate that fact, and to encourage readers to concentrate on filling in the gaps in the missing entries instead of just adding new ones, there’s a \$1,000 prize for the best solution to an open problem posed in an OEIS entry. The announcement…
How I Wish I Could Celebrate Pi
People with an interest in date coincidences are probably already getting themselves slightly over-excited about the fact that this month will include what can only be described as Ultimate π Day. That is, on 14th March 2015, written under certain circumstances by some people as 3/14/15, we’ll be celebrating the closest that the date can…
Puzzlebomb – March 2015
Puzzlebomb is a monthly puzzle compendium. Issue 39 of Puzzlebomb, for March 2015, can be found here: Puzzlebomb – Issue 39 – March 2015 The solutions to Issue 39 can be found here: Puzzlebomb – Issue 39 – March 2015 – Solutions Previous issues of Puzzlebomb, and their solutions, can be found here.
Wolfram|Alpha can’t. But CP can!
Christian Perfect has turned into a one-man plug for the holes in Wolfram|Alpha.
Each pair of smartphones has exactly one Dobble app in common
Card game fans might be familiar with the game of Dobble, in which a set of cards featuring symbols is laid out on the table, and family members tear each other’s hands off/eyes out in order to find the one symbol a given pair of cards has in common. Well, it’s now also available virtually!
From the Mailbag: Golfing Combinatorics
A reader’s Dad is in a combinatoric golf conundrum! Katie Steckles tries to help, with maths.
The Topological Tverberg Conjecture is False
Attention, Topological Combinatorialists! The topological Tverberg Conjecture, described as ‘a holy grail of topological combinatorics’, is false. The conjecture says that any continuous map of a simplex of dimension $(r−1)(d+1)$ to $\mathbb{R}^d$ maps points from $r$ disjoint faces of the simplex to the same point in $\mathbb{R}^d$. In certain cases the conjecture has been proven true,…