See for detailed explanation, webpage pan 4x4 in 6x6
Take a 18x18 magic square and add 38 to all numbers to get the 18x18 inlay and construct the 20x20 border.
The final result is:
18x18 in 20x20 magic square
24 |
2 |
5 |
11 |
17 |
19 |
27 |
29 |
31 |
395 |
392 |
389 |
387 |
386 |
380 |
376 |
373 |
368 |
364 |
35 |
398 |
39 |
40 |
54 |
359 |
358 |
357 |
356 |
49 |
48 |
47 |
352 |
351 |
350 |
349 |
42 |
41 |
361 |
56 |
3 |
394 |
57 |
58 |
72 |
71 |
340 |
339 |
338 |
337 |
336 |
335 |
334 |
333 |
332 |
61 |
60 |
59 |
73 |
74 |
7 |
391 |
309 |
310 |
77 |
323 |
88 |
87 |
86 |
82 |
318 |
317 |
85 |
81 |
80 |
313 |
312 |
90 |
325 |
326 |
10 |
385 |
308 |
292 |
306 |
305 |
106 |
105 |
104 |
100 |
300 |
101 |
103 |
99 |
98 |
97 |
294 |
293 |
307 |
291 |
16 |
383 |
290 |
289 |
275 |
276 |
286 |
123 |
122 |
118 |
119 |
120 |
121 |
117 |
116 |
277 |
125 |
288 |
274 |
273 |
18 |
378 |
272 |
271 |
257 |
258 |
259 |
134 |
140 |
136 |
137 |
138 |
139 |
135 |
141 |
142 |
269 |
270 |
256 |
255 |
23 |
375 |
254 |
253 |
239 |
240 |
241 |
242 |
153 |
154 |
155 |
156 |
157 |
158 |
159 |
160 |
161 |
252 |
238 |
237 |
26 |
371 |
219 |
235 |
167 |
168 |
169 |
170 |
171 |
172 |
173 |
174 |
175 |
230 |
231 |
232 |
233 |
234 |
220 |
236 |
30 |
369 |
201 |
217 |
216 |
215 |
187 |
188 |
189 |
190 |
191 |
192 |
193 |
194 |
195 |
214 |
204 |
203 |
202 |
218 |
32 |
38 |
183 |
199 |
198 |
186 |
205 |
206 |
207 |
208 |
209 |
210 |
211 |
212 |
213 |
196 |
197 |
185 |
184 |
200 |
363 |
36 |
182 |
181 |
221 |
222 |
223 |
224 |
225 |
226 |
227 |
228 |
229 |
176 |
177 |
178 |
179 |
180 |
166 |
165 |
365 |
34 |
164 |
163 |
149 |
150 |
151 |
152 |
243 |
247 |
245 |
246 |
244 |
248 |
249 |
250 |
251 |
162 |
148 |
147 |
367 |
22 |
146 |
145 |
131 |
132 |
133 |
260 |
261 |
265 |
263 |
264 |
262 |
266 |
267 |
268 |
143 |
144 |
130 |
129 |
379 |
20 |
128 |
112 |
126 |
114 |
124 |
278 |
279 |
283 |
282 |
281 |
280 |
284 |
285 |
115 |
287 |
113 |
127 |
111 |
381 |
13 |
93 |
94 |
108 |
107 |
295 |
303 |
297 |
301 |
102 |
299 |
298 |
302 |
296 |
304 |
96 |
95 |
109 |
110 |
388 |
8 |
75 |
76 |
311 |
89 |
322 |
321 |
320 |
319 |
84 |
83 |
316 |
315 |
314 |
79 |
78 |
324 |
91 |
92 |
393 |
4 |
344 |
328 |
342 |
341 |
70 |
69 |
68 |
67 |
66 |
65 |
64 |
63 |
62 |
331 |
330 |
329 |
343 |
327 |
397 |
1 |
345 |
346 |
360 |
53 |
52 |
51 |
50 |
355 |
354 |
353 |
46 |
45 |
44 |
43 |
348 |
347 |
55 |
362 |
400 |
366 |
399 |
396 |
390 |
384 |
382 |
374 |
372 |
370 |
6 |
9 |
12 |
14 |
15 |
21 |
25 |
28 |
33 |
37 |
377 |
Use this method to construct inlaid magic squares of even order. See 6x6, 8x8, 10x10, 12x12, 14x14, 16x16, 18x18, 20x20, 22x22, 24x24, 26x26, 28x28, 30x30 & 32x32