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 A137385 Number of errors that occur when choosing n as modulus in French INSEE code (0
 8190, 7600, 2184, 6810, 7246, 2024, 994, 5956, 182, 7128, 336, 1806, 448, 920, 1932, 5068, 375, 168, 330, 6578, 196, 312, 274, 1579, 6250, 414, 0, 821, 200, 1908, 244, 4246, 84, 342, 878, 154, 112, 301, 140, 5844, 134, 182, 122, 276, 168, 255, 111, 1347, 125, 6248, 92, 363, 104, 0, 294, 715, 85, 183, 75, 1758, 92, 223, 0, 3492, 392, 78, 70, 300, 64, 864, 110, 140, 63, 108, 1673, 262, 28, 130, 65, 5054, 0, 120, 63, 160, 323, 111, 51, 238, 57, 168, 28, 225, 77, 102, 286, 1132, 74, 120, 0 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS The most frequent errors are: - permutation between 2 ranks - error in one rank LINKS Author?, Les-mathematiques.net [Broken link?] EXAMPLE Actual n is 97. It generates 74 errors. Best choices could be 27, 54, 63, 81 or 99 instead of 97. PROG (Python) # Replace leading dots by spaces .for cle in range(1, 100): ... n=0 ... for r1 in range(1, 14): ....... for r2 in range(r1, 14): ............ur1=cle-(10**(13-r1))%cle ............ur2=cle-(10**(13-r2))%cle ............for c1 in range(10): ............... for c2 in range(10): ................... if c1==c2: ........................dif=1 ................... else: ........................dif=(c1*ur1-c2*ur2)%cle ................... if dif==0: ........................n=n+1 ... print cle, ':', n CROSSREFS Sequence in context: A235095 A283954 A250939 * A108093 A051334 A145592 Adjacent sequences:  A137382 A137383 A137384 * A137386 A137387 A137388 KEYWORD fini,full,nonn AUTHOR Sébastien Dumortier, Apr 26 2008 STATUS approved

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Last modified July 20 15:59 EDT 2019. Contains 325185 sequences. (Running on oeis4.)