There is a fine tradition of mathematicians with mathematics on their tombstones. What immediately springs to mind is Ludolph Van Ceulen and Jacob Bernoulli. Van Ceulen calculated $\pi$ to 35 decimal places; his grave carried both his lower bound of 3.14159265358979323846264338327950288 and his upper bound of 3.14159265358979323846264338327950289. Bernoulli asked for a logarithmic spiral on his gravestone, but the stonemasons etched an Archimedean spiral instead. Googling to fill in the details in my hazy memory, I discovered a blog post by Dave Richeson with the details of several more mathematical monuments.
Into this fine tradition steps Angela Robinson, widow of Shell numerical analyst and Sudoku enthusiast Allan Robinson.