Promoting Mathematical Thinking
  • Promoting Mathematical Thinking ... the home of John Mason & Anne Watson
    • IMP
    • PMThetaAtHome
    • Anne Watson >
      • Anne's PodCasts
      • Publications
      • Concerns
      • ATM triangles
      • Dose of Don
      • ToulouseGrids
    • AW & JM Joint Presentations
    • John Mason >
      • JHM Bio
      • Piranesi Inspired Pictures
      • JHM Presentations
      • Studies
      • Other Projects
      • JHM Publications
      • JHM-Draughty-Drafts
      • Applets >
        • Reasoning Without Arithmetic
        • Number Formats
        • Reasoning about Numbers
        • Reasoning about Graphs of Functions
        • Fractions & Decimals
        • More or Less Grids
        • Calgary Grids
        • Related Polygons
        • Polynomial Studies
        • Polygonal Projections
        • Sundaram Grids
        • Geometrical Applets
        • Structured Variation Grids
        • Animated Situations
        • Outer Inner Area Ratios
        • Clocks
        • Balancing Tasks
        • Linear Algebra

Sundaram Grids


Picture
Here you see the beginnings of a grid that extends arbitrarily far to the right and up.

In 1932, Sundaram noticed that if you take any entry in the grid, double it and add 1, the result must be composite. Is this true?

The applet gives access to other similar grids in a search for similar conjectures.

Applet    Notes
Proudly powered by Weebly