A concentric magic square is nice. A concentric magic square with diamond is even better; see i.e. the 15x15 Al Antaakii concentric magic square with diamond. In the diamond are alle odd numbers (and outside the diamond are the even numbers).
How to construct a concentric magic square with diamond? Puzzle in EXCEL and see the result below:
27x27 concentric magic square with diamond
254 |
472 |
470 |
468 |
466 |
266 |
462 |
270 |
456 |
278 |
448 |
284 |
444 |
1 |
288 |
440 |
292 |
436 |
296 |
432 |
300 |
428 |
304 |
306 |
422 |
398 |
474 |
310 |
164 |
562 |
560 |
172 |
556 |
176 |
526 |
180 |
548 |
184 |
544 |
5 |
723 |
9 |
188 |
540 |
192 |
536 |
196 |
532 |
200 |
528 |
524 |
216 |
564 |
420 |
312 |
522 |
100 |
104 |
624 |
108 |
620 |
112 |
616 |
116 |
612 |
17 |
711 |
21 |
707 |
25 |
120 |
608 |
124 |
604 |
128 |
600 |
598 |
492 |
628 |
208 |
418 |
314 |
210 |
596 |
52 |
56 |
672 |
60 |
668 |
64 |
664 |
37 |
691 |
41 |
687 |
45 |
683 |
49 |
68 |
660 |
72 |
656 |
654 |
410 |
676 |
134 |
520 |
416 |
316 |
518 |
594 |
652 |
20 |
24 |
704 |
28 |
700 |
65 |
663 |
69 |
659 |
73 |
655 |
77 |
651 |
81 |
32 |
696 |
694 |
336 |
708 |
78 |
136 |
212 |
414 |
412 |
214 |
592 |
80 |
692 |
4 |
8 |
720 |
167 |
101 |
627 |
105 |
623 |
109 |
619 |
113 |
615 |
117 |
611 |
718 |
224 |
724 |
38 |
650 |
138 |
516 |
318 |
334 |
512 |
140 |
648 |
40 |
716 |
728 |
143 |
583 |
579 |
575 |
571 |
567 |
165 |
175 |
179 |
183 |
187 |
191 |
195 |
454 |
14 |
690 |
82 |
590 |
218 |
396 |
408 |
220 |
588 |
84 |
688 |
16 |
599 |
223 |
243 |
239 |
235 |
231 |
227 |
513 |
515 |
519 |
523 |
527 |
531 |
219 |
131 |
714 |
42 |
646 |
142 |
510 |
322 |
324 |
508 |
144 |
644 |
44 |
171 |
145 |
533 |
463 |
449 |
453 |
457 |
461 |
465 |
257 |
253 |
249 |
245 |
263 |
197 |
585 |
559 |
686 |
86 |
586 |
222 |
406 |
404 |
226 |
584 |
88 |
83 |
121 |
149 |
529 |
247 |
303 |
445 |
441 |
437 |
301 |
305 |
309 |
313 |
431 |
483 |
201 |
581 |
609 |
647 |
642 |
146 |
504 |
326 |
328 |
502 |
148 |
679 |
645 |
607 |
153 |
525 |
251 |
315 |
327 |
317 |
321 |
401 |
397 |
393 |
399 |
415 |
479 |
205 |
577 |
123 |
85 |
51 |
582 |
228 |
402 |
400 |
230 |
27 |
677 |
643 |
125 |
157 |
521 |
255 |
311 |
411 |
383 |
375 |
345 |
343 |
379 |
319 |
419 |
475 |
209 |
573 |
605 |
87 |
53 |
703 |
500 |
330 |
364 |
719 |
701 |
55 |
641 |
603 |
161 |
517 |
259 |
307 |
407 |
353 |
359 |
373 |
363 |
377 |
323 |
423 |
471 |
213 |
569 |
127 |
89 |
675 |
29 |
11 |
366 |
727 |
717 |
31 |
673 |
91 |
129 |
169 |
221 |
261 |
433 |
405 |
349 |
369 |
365 |
361 |
381 |
325 |
297 |
469 |
509 |
561 |
601 |
639 |
57 |
699 |
13 |
3 |
390 |
15 |
697 |
59 |
637 |
589 |
557 |
225 |
459 |
435 |
335 |
389 |
367 |
357 |
371 |
341 |
395 |
295 |
271 |
505 |
173 |
141 |
93 |
671 |
33 |
715 |
340 |
342 |
498 |
35 |
669 |
95 |
597 |
553 |
229 |
455 |
439 |
339 |
351 |
355 |
385 |
387 |
347 |
391 |
291 |
275 |
501 |
177 |
133 |
635 |
61 |
695 |
232 |
388 |
386 |
234 |
580 |
63 |
633 |
595 |
549 |
233 |
451 |
443 |
331 |
413 |
409 |
329 |
333 |
337 |
403 |
287 |
279 |
497 |
181 |
135 |
97 |
667 |
150 |
496 |
344 |
346 |
494 |
152 |
640 |
99 |
137 |
545 |
237 |
447 |
299 |
285 |
289 |
293 |
429 |
425 |
421 |
417 |
427 |
283 |
493 |
185 |
593 |
631 |
90 |
578 |
236 |
384 |
382 |
240 |
576 |
92 |
684 |
591 |
541 |
241 |
467 |
281 |
277 |
273 |
269 |
265 |
473 |
477 |
481 |
485 |
267 |
489 |
189 |
139 |
46 |
638 |
154 |
490 |
348 |
350 |
488 |
156 |
636 |
48 |
712 |
193 |
511 |
487 |
491 |
495 |
499 |
503 |
217 |
215 |
211 |
207 |
203 |
199 |
507 |
537 |
18 |
682 |
94 |
574 |
242 |
380 |
378 |
246 |
572 |
96 |
680 |
486 |
276 |
587 |
147 |
151 |
155 |
159 |
163 |
565 |
555 |
551 |
547 |
543 |
539 |
535 |
2 |
244 |
50 |
634 |
158 |
484 |
352 |
354 |
482 |
160 |
632 |
450 |
6 |
722 |
10 |
563 |
629 |
103 |
625 |
107 |
621 |
111 |
617 |
115 |
613 |
119 |
12 |
506 |
726 |
280 |
98 |
570 |
248 |
376 |
374 |
250 |
568 |
392 |
22 |
706 |
26 |
702 |
30 |
665 |
67 |
661 |
71 |
657 |
75 |
653 |
79 |
649 |
698 |
34 |
36 |
394 |
710 |
338 |
162 |
480 |
356 |
358 |
478 |
552 |
54 |
674 |
58 |
670 |
62 |
666 |
66 |
693 |
39 |
689 |
43 |
685 |
47 |
681 |
662 |
70 |
658 |
74 |
76 |
320 |
678 |
178 |
252 |
372 |
370 |
272 |
102 |
626 |
106 |
622 |
110 |
618 |
114 |
614 |
118 |
713 |
19 |
709 |
23 |
705 |
610 |
122 |
606 |
126 |
602 |
130 |
132 |
238 |
630 |
458 |
360 |
362 |
166 |
168 |
170 |
558 |
174 |
554 |
204 |
550 |
182 |
546 |
186 |
725 |
7 |
721 |
542 |
190 |
538 |
194 |
534 |
198 |
530 |
202 |
206 |
514 |
566 |
368 |
256 |
258 |
260 |
262 |
264 |
464 |
268 |
460 |
274 |
452 |
282 |
446 |
286 |
729 |
442 |
290 |
438 |
294 |
434 |
298 |
430 |
302 |
426 |
424 |
308 |
332 |
476 |
Puzzle yourself using the EXCEL download below.