The search continues.

Infinite Search Space hosted recreational maths and programming contests in 2011 and 2012: hard puzzles that ran for months, were scored to the last digit, and were played mostly for bragging rights. It's coming back, with new contests, and a classic room where the old records can finally be beaten.

With a nearly infinite search space, only the clever will find an edge.

The first time around

Four contests, players from all over the world

Orchard Planting

Sep – Dec 2011

Plant N trees on whole-number points to make as many rows of exactly four as possible.

WinnerIl Brigante Pennastorta

SameGame

Jan – Apr 2012

Clear 25 boards of coloured tiles for the highest possible score.

WinnerWes Sampson

Monochromatic Squares

May – Aug 2012

Colour the largest grid you can, with up to 21 colours, so no rectangle has four corners alike.

WinnerAlex Chernov

Prime Sums

Late 2012

A prime-number puzzle that ended in a dead heat at the top.

Joint winnersDmitry Kamenetsky & Alex Chernov

Still remembered

Where the contests left a mark

The On-Line Encyclopedia of Integer Sequences, A172992, records the integer orchard problem with results from the 2011 contest and its follow-up mini-contest.
Fenner, Gasarch, Glover and Purewal's paper Rectangle Free Coloring of Grids describes the grid-colouring contest devised by Neil Brewer and Dmitry Kamenetsky, and uses two results from its discussions.