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Old 2007-01-23, 10:47   #6
Citrix
 
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Jun 2003

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Found another lowest number =1307. 512 is a trivial solution, this is not.
All below checked to n=1000.

101 -->done to 4500
167
206
218
236
257
287
305
353
365
368
383
395
416
461
467
497
512 --> Can be removed trivially
518
542
578
626
635
647
695
698
752
758
764
773
788
801
812
836
842
867
869
878
887
899
908
914
917
932
947
948
954
992
1004
1052
1058
1073
1079
1082
1097
1112
1139
1142
1187
1193
1232
1262
1277
1286
Primes

2*104^1233+1
2*122^755+1
2*263^957+1
2*38^2729+1
2*821^945+1
2*845^877+1
2*926^765+1
2*968^917+1
2*1022^727+1
2*1028^669+1
2*1181^789+1
2*1253^697+1
2*1283^765+1

Will continue to prove 1307 is the smallest such number.

Have not found a -1 number upto 250,000. Not sure if there is one. may be the same covering set as +1 can be used. Need help here, if anyone can offer.

Last fiddled with by Citrix on 2007-01-23 at 11:44
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