Keith Briggs (mathematician)

• The most accurate calculation of the Feigenbaum constants, which was published in A precise calculation of the Feigenbaum constants, Mathematics of Computation 57, 435-439.
• The worst known badly approximable irrational pair.
• The simplest known universal differential equation.
• The largest number of contributions in the last 5 years to Sloane's On-Line Encyclopedia of Integer Sequences. Many of these have involved major computations, such as the number of unlabelled graphs on up to 140 nodes.
• The computation of the longest sequences of colossally abundant and superabundant numbers, and their application to a test of the Riemann Hypothesis.