1
a) Place numbers 1 to 25 on the cells of this board so that each of them, except for 1 and 2, is the sum of precisely two of its (up to 8) neighbors.
b) Do likewise with the numbers 1 to 36 in a 6 x 6 board? ΒΏCan a similar outcome be achieved in a square board of any larger size?
Puzzle due to G...