Look at the following row of numbers:
10, 15, 21, 4, 5
They are arranged so that each pair of adjacent numbers adds up to a square number:
10+15=25
15+21=36
21+4=25
4+5=9
Can you arrange the numbers 1 to 17 in a row in the same way, so that each adjacent pair adds up to a square number?
Source: NRICH
Department