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 A079339 Least k such that the decimal representation of k*n contains only 1's and 0's. 34
 1, 5, 37, 25, 2, 185, 143, 125, 12345679, 1, 1, 925, 77, 715, 74, 625, 653, 61728395, 579, 5, 481, 5, 4787, 4625, 4, 385, 40781893, 3575, 37969, 37, 3581, 3125, 3367, 3265, 286, 308641975, 3, 2895, 259, 25, 271, 2405, 25607, 25, 24691358, 23935, 213, 23125 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS From David Amar (dpamar(AT)gmail.com), Jul 12 2010: (Start) This sequence is well defined. In the n+1 first repunits (see A002275), there are at least 2 numbers that have the same value modulo n (pigeonhole principle). The difference between those two numbers contains only 1's and 0's in decimal representation. (End) REFERENCES Popular Computing (Calabasas, CA), Z-Sequences, Vol. 4 (No. 34, A pr 1976), pages PC36-4 to PC37-6, but there are many errors (cf. A257343, A257344). LINKS Robert G. Wilson v, Table of n, a(n) for n = 1..10000 (terms 1..1999 from T. D. Noe, terms 2000..9998 from N. J. A. Sloane [based on A004290]) FORMULA a(n) = A004290(n)/n. a(n) < 10^(n+1) / (9n). - Charles R Greathouse IV, Jan 09 2012 EXAMPLE 3*37 = 111 and no integer k < 37 has this property, hence a(3)=37. PROG (PARI) d(n, i)=floor(n/10^(i-1))-10*floor(n/10^i); test(n)=sum(i=1, ceil(log(n)/log(10)), if(d(n, i)*(1-d(n, i)), 1, 0)); a(n)=if(n<0, 0, s=1; while(test(n*s)>0, s++); s) CROSSREFS Cf. A004290, A070189, A078241-A078248, A096681-A096688, A257343, A257344, A257345. Sequence in context: A174507 A119483 A157809 * A257343 A244927 A043075 Adjacent sequences:  A079336 A079337 A079338 * A079340 A079341 A079342 KEYWORD base,nonn AUTHOR Benoit Cloitre, Feb 13 2003 EXTENSIONS More terms from Vladeta Jovovic and Matthew Vandermast, Feb 14 2003 Definition simplified by Franklin T. Adams-Watters, Jan 09 2012 STATUS approved

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