examples

k = 1
for y in range(6):
    print('  '*(5-y), end='')
    #for x in range(y, -1, -1):
    #    print(k+x, end=' ')
    for x in range(k+y, k-1, -1):
        print(x, end=' ')
    print()
    k += y+1

# ----------------------------------

k = 1
for y in range(6):
    print('  '*(5-y), end='')
    a = [str(x) for x in range(k+y, k-1, -1)]
    print(' '.join(a))
    k += y+1