Dear Web-surfer,
You are indeed a dedicated vampire number fan :-)
Here are the 48 ten digit vampire numbers that are disqualified for being virtual twins, along with their factors. This list contains no triple fang vampire numbers.
The search for all 112,024 ten digit vampire number candidates was accomplished using 16 IBM ThinkPad laptop computers running for about 40 hours, over a weekend. Each computer searched a portion of the 4 billion calculations that had to be performed. This would have taken one computer about 26 days of 24 hrs/day running. My thanks to the students listed in the table for assisting with the search.
(Update: June 2007 - Today the search takes 22 hours running a Visual Basic program on a 2.0 GHz desktop machine. Still, There is no mathematical elegance here, just simple brute force, multiplying every possibility and checking the result.)
| The 48 Valid and virtual 10 digit vampire numbers |
| 12110 x 84077 = 1018172470 12011 x 84770 = 1018172470 |
| 27531 x 39204 = 1079325324 27324 x 39501 = 1079325324 |
| 11009 x 99110 = 1091101990 11990 x 91001 = 1091101990 |
| 13209 x 82614 = 1091248326 11802 x 92463 = 1091248326 |
| 18603 x 60210 = 1120086630 18063 x 62010 = 1120086630 |
| 15201 x 76095 = 1156720095 15219 x 76005 = 1156720095 |
| 14315 x 82070 = 1174832050 14150 x 83027 = 1174832050 |
| 26730 x 46512 = 1243265760 26163 x 47520 = 1243265760 |
| 25005 x 50190 = 1255000950 25095 x 50010 = 1255000950 |
| 25800 x 50196 = 1295056800 25098 x 51600 = 1295056800 |
| 16143 x 81570 = 1316784510 16314 x 80715 = 1316784510 |
| 16530 x 87024 = 1438506720 17052 x 84360 = 1438506720 |
| 19250 x 87269 = 1679928250 21098 x 79625 = 1679928250 |
| 19487 x 86672 = 1688977264 21668 x 77948 = 1688977264 |
| 19260 x 87813 = 1691278380 21186 x 79830 = 1691278380 |
| 29841 x 56802 = 1695028482 28401 x 59682 = 1695028482 |
| 29970 x 57681 = 1728699570 28971 x 59670 = 1728699570 |
| 35802 x 51750 = 1852753500 35100 x 52785 = 1852753500 |
| 37620 x 51948 = 1954283760 37962 x 51480 = 1954283760 |
| 38160 x 57024 = 2176035840 38016 x 57240 = 2176035840 |
| 27270 x 81081 = 2211078870 27027 x 81810 = 2211078870 |
| 30848 x 77210 = 2381774080 30884 x 77120 = 2381774080 |
| 34446 x 69288 = 2386694448 34644 x 68892 = 2386694448 |
| 24653 x 98120 = 2418952360 24530 x 98612 = 2418952360 |
| 33561 x 94860 = 3183596460 33660 x 94581 = 3183596460 |
| 39675 x 87450 = 3469578750 36570 x 94875 = 3469578750 |
| 43140 x 80682 = 3480621480 40341 x 86280 = 3480621480 |
| 41325 x 86250 = 3564281250 43125 x 82650 = 3564281250 |
| 45236 x 79184 = 3581967424 45248 x 79163 = 3581967424 |
| 36060 x 99561 = 3590169660 39666 x 90510 = 3590169660 |
| 53760 x 68388 = 3676538880 53376 x 68880 = 3676538880 |
| 54723 x 67380 = 3687235740 57273 x 64380 = 3687235740 |
| 45402 x 89040 = 4042594080 44520 x 90804 = 4042594080 |
| 47241 x 89424 = 4224479184 44712 x 94482 = 4224479184 |
| 45117 x 94230 = 4251374910 47115 x 90234 = 4251374910 |
| 46143 x 92862 = 4284931266 46431 x 92286 = 4284931266 |
| 56487 x 77325 = 4367857275 58767 x 74325 = 4367857275 |
| 47538 x 94239 = 4479933582 48393 x 92574 = 4479933582 |
| 48050 x 95648 = 4595886400 48608 x 94550 = 4595886400 |
| 62913 x 73644 = 4633164972 64923 x 71364 = 4633164972 |
| 47628 x 99081 = 4719029868 48069 x 98172 = 4719029868 |
| 56052 x 84780 = 4752088560 56520 x 84078 = 4752088560 |
| 60552 x 98928 = 5990288256 65952 x 90828 = 5990288256 |
| 64107 x 93825 = 6014839275 63801 x 94275 = 6014839275 |
| 75816 x 81432 = 6173848512 75168 x 82134 = 6173848512 |
| 74480 x 93626 = 6973264480 73682 x 94640 = 6973264480 |
| 83670 x 95205 = 7965802350 86550 x 92037 = 7965802350 |
| 93201 x 97950 = 9129037950 92073 x 99150 = 9129037950 |
| Students helping with the 10 digit search |
| Paul Batyushkov |
| Henry Chan |
| Drew Gauthier |
| Joel Langlois |
| Karina Viglianti |
| Sebastian Warner |
| Baldwin Yeung |
| David Walton |
| Donny Carr |
| Ryan Olgivie |
| Marc Vollebekk |
| Tala Semaan |
| Akofa Jurschewsky |
| Ms. Jan Myers |
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