Marios Mamzeris shows us that you can transform a odd square with sequencial numbers into a symmetric magic square in two steps (https://www.oddmagicsquares.com/):
Step 1, horizontal swap
< | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 2 | 3 | 4 | 5 | 6 | 7 | 1 | ||
< | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 10 | 11 | 12 | 13 | 14 | 8 | 9 | ||
< | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 18 | 19 | 20 | 21 | 15 | 16 | 17 | ||
22 | 23 | 24 | 25 | 26 | 27 | 28 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | |||
29 | 30 | 31 | 32 | 33 | 34 | 35 | > | 33 | 34 | 35 | 29 | 30 | 31 | 32 | ||
36 | 37 | 38 | 39 | 40 | 41 | 42 | > | 41 | 42 | 36 | 37 | 38 | 39 | 40 | ||
43 | 44 | 45 | 46 | 47 | 48 | 49 | > | 49 | 43 | 44 | 45 | 46 | 47 | 48 |
Step 2, vertical swap
^ | ^ | ^ | ||||||||||||||
2 | 3 | 4 | 5 | 6 | 7 | 1 | 10 | 19 | 24 | 5 | 30 | 39 | 48 | |||
10 | 11 | 12 | 13 | 14 | 8 | 9 | 18 | 23 | 35 | 13 | 38 | 47 | 1 | |||
18 | 19 | 20 | 21 | 15 | 16 | 17 | 22 | 34 | 36 | 21 | 46 | 7 | 9 | |||
22 | 23 | 24 | 25 | 26 | 27 | 28 | 33 | 42 | 44 | 25 | 6 | 8 | 17 | |||
33 | 34 | 35 | 29 | 30 | 31 | 32 | 41 | 43 | 4 | 29 | 14 | 16 | 28 | |||
41 | 42 | 36 | 37 | 38 | 39 | 40 | 49 | 3 | 12 | 37 | 15 | 27 | 32 | |||
49 | 43 | 44 | 45 | 46 | 47 | 48 | 2 | 11 | 20 | 45 | 26 | 31 | 40 | |||
v | v | v |
See 3x3, 5x5, 7x7, 9x9, 11x11, 13x13, 15x15, 17x17, 19x19, 21x21, 23x23, 25x25, 27x27, 29x29 and 31x31