See below the key to construct an ultramagic 16x16 square.
Take 1x number from first grid
1 | 15 | 14 | 4 | 5 | 11 | 10 | 8 | 8 | 10 | 11 | 5 | 4 | 14 | 15 | 1 |
16 | 2 | 3 | 13 | 12 | 6 | 7 | 9 | 9 | 7 | 6 | 12 | 13 | 3 | 2 | 16 |
1 | 15 | 14 | 4 | 5 | 11 | 10 | 8 | 8 | 10 | 11 | 5 | 4 | 14 | 15 | 1 |
16 | 2 | 3 | 13 | 12 | 6 | 7 | 9 | 9 | 7 | 6 | 12 | 13 | 3 | 2 | 16 |
1 | 15 | 14 | 4 | 5 | 11 | 10 | 8 | 8 | 10 | 11 | 5 | 4 | 14 | 15 | 1 |
16 | 2 | 3 | 13 | 12 | 6 | 7 | 9 | 9 | 7 | 6 | 12 | 13 | 3 | 2 | 16 |
1 | 15 | 14 | 4 | 5 | 11 | 10 | 8 | 8 | 10 | 11 | 5 | 4 | 14 | 15 | 1 |
16 | 2 | 3 | 13 | 12 | 6 | 7 | 9 | 9 | 7 | 6 | 12 | 13 | 3 | 2 | 16 |
1 | 15 | 14 | 4 | 5 | 11 | 10 | 8 | 8 | 10 | 11 | 5 | 4 | 14 | 15 | 1 |
16 | 2 | 3 | 13 | 12 | 6 | 7 | 9 | 9 | 7 | 6 | 12 | 13 | 3 | 2 | 16 |
1 | 15 | 14 | 4 | 5 | 11 | 10 | 8 | 8 | 10 | 11 | 5 | 4 | 14 | 15 | 1 |
16 | 2 | 3 | 13 | 12 | 6 | 7 | 9 | 9 | 7 | 6 | 12 | 13 | 3 | 2 | 16 |
1 | 15 | 14 | 4 | 5 | 11 | 10 | 8 | 8 | 10 | 11 | 5 | 4 | 14 | 15 | 1 |
16 | 2 | 3 | 13 | 12 | 6 | 7 | 9 | 9 | 7 | 6 | 12 | 13 | 3 | 2 | 16 |
1 | 15 | 14 | 4 | 5 | 11 | 10 | 8 | 8 | 10 | 11 | 5 | 4 | 14 | 15 | 1 |
16 | 2 | 3 | 13 | 12 | 6 | 7 | 9 | 9 | 7 | 6 | 12 | 13 | 3 | 2 | 16 |
+ 16x [number -/- 1] from second grid (= reflection of first grid)
1 | 16 | 1 | 16 | 1 | 16 | 1 | 16 | 1 | 16 | 1 | 16 | 1 | 16 | 1 | 16 |
15 | 2 | 15 | 2 | 15 | 2 | 15 | 2 | 15 | 2 | 15 | 2 | 15 | 2 | 15 | 2 |
14 | 3 | 14 | 3 | 14 | 3 | 14 | 3 | 14 | 3 | 14 | 3 | 14 | 3 | 14 | 3 |
4 | 13 | 4 | 13 | 4 | 13 | 4 | 13 | 4 | 13 | 4 | 13 | 4 | 13 | 4 | 13 |
5 | 12 | 5 | 12 | 5 | 12 | 5 | 12 | 5 | 12 | 5 | 12 | 5 | 12 | 5 | 12 |
11 | 6 | 11 | 6 | 11 | 6 | 11 | 6 | 11 | 6 | 11 | 6 | 11 | 6 | 11 | 6 |
10 | 7 | 10 | 7 | 10 | 7 | 10 | 7 | 10 | 7 | 10 | 7 | 10 | 7 | 10 | 7 |
8 | 9 | 8 | 9 | 8 | 9 | 8 | 9 | 8 | 9 | 8 | 9 | 8 | 9 | 8 | 9 |
8 | 9 | 8 | 9 | 8 | 9 | 8 | 9 | 8 | 9 | 8 | 9 | 8 | 9 | 8 | 9 |
10 | 7 | 10 | 7 | 10 | 7 | 10 | 7 | 10 | 7 | 10 | 7 | 10 | 7 | 10 | 7 |
11 | 6 | 11 | 6 | 11 | 6 | 11 | 6 | 11 | 6 | 11 | 6 | 11 | 6 | 11 | 6 |
5 | 12 | 5 | 12 | 5 | 12 | 5 | 12 | 5 | 12 | 5 | 12 | 5 | 12 | 5 | 12 |
4 | 13 | 4 | 13 | 4 | 13 | 4 | 13 | 4 | 13 | 4 | 13 | 4 | 13 | 4 | 13 |
14 | 3 | 14 | 3 | 14 | 3 | 14 | 3 | 14 | 3 | 14 | 3 | 14 | 3 | 14 | 3 |
15 | 2 | 15 | 2 | 15 | 2 | 15 | 2 | 15 | 2 | 15 | 2 | 15 | 2 | 15 | 2 |
1 | 16 | 1 | 16 | 1 | 16 | 1 | 16 | 1 | 16 | 1 | 16 | 1 | 16 | 1 | 16 |
= ultra magic 16x16 square
1 | 255 | 14 | 244 | 5 | 251 | 10 | 248 | 8 | 250 | 11 | 245 | 4 | 254 | 15 | 241 |
240 | 18 | 227 | 29 | 236 | 22 | 231 | 25 | 233 | 23 | 230 | 28 | 237 | 19 | 226 | 32 |
209 | 47 | 222 | 36 | 213 | 43 | 218 | 40 | 216 | 42 | 219 | 37 | 212 | 46 | 223 | 33 |
64 | 194 | 51 | 205 | 60 | 198 | 55 | 201 | 57 | 199 | 54 | 204 | 61 | 195 | 50 | 208 |
65 | 191 | 78 | 180 | 69 | 187 | 74 | 184 | 72 | 186 | 75 | 181 | 68 | 190 | 79 | 177 |
176 | 82 | 163 | 93 | 172 | 86 | 167 | 89 | 169 | 87 | 166 | 92 | 173 | 83 | 162 | 96 |
145 | 111 | 158 | 100 | 149 | 107 | 154 | 104 | 152 | 106 | 155 | 101 | 148 | 110 | 159 | 97 |
128 | 130 | 115 | 141 | 124 | 134 | 119 | 137 | 121 | 135 | 118 | 140 | 125 | 131 | 114 | 144 |
113 | 143 | 126 | 132 | 117 | 139 | 122 | 136 | 120 | 138 | 123 | 133 | 116 | 142 | 127 | 129 |
160 | 98 | 147 | 109 | 156 | 102 | 151 | 105 | 153 | 103 | 150 | 108 | 157 | 99 | 146 | 112 |
161 | 95 | 174 | 84 | 165 | 91 | 170 | 88 | 168 | 90 | 171 | 85 | 164 | 94 | 175 | 81 |
80 | 178 | 67 | 189 | 76 | 182 | 71 | 185 | 73 | 183 | 70 | 188 | 77 | 179 | 66 | 192 |
49 | 207 | 62 | 196 | 53 | 203 | 58 | 200 | 56 | 202 | 59 | 197 | 52 | 206 | 63 | 193 |
224 | 34 | 211 | 45 | 220 | 38 | 215 | 41 | 217 | 39 | 214 | 44 | 221 | 35 | 210 | 48 |
225 | 31 | 238 | 20 | 229 | 27 | 234 | 24 | 232 | 26 | 235 | 21 | 228 | 30 | 239 | 17 |
16 | 242 | 3 | 253 | 12 | 246 | 7 | 249 | 9 | 247 | 6 | 252 | 13 | 243 | 2 | 256 |
This magic square is panmagic, symmetric, 2x2 compact and each 1/4 row/column gives 1/4 of the magic sum.
You can use this key to construct magic squares which are a multiple of 4 from 8x8 to infinity. See 8x8, 12x12, 16x16, 20x20, 24x24, 28x28 and 32x32