# Floyd's triangle is a right-angled triangular of natural numbers
rows = 7
n = 1
for i in range(1, rows + 1):
for j in range(1, i + 1):
print(n, ' ', end='')
n += 1
print()
'''
run:
1
2 3
4 5 6
7 8 9 10
11 12 13 14 15
16 17 18 19 20 21
22 23 24 25 26 27 28
'''