The OEIS is supported by the many generous donors to the OEIS Foundation.

 Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 59th year, we have over 358,000 sequences, and we’ve crossed 10,300 citations (which often say “discovered thanks to the OEIS”). Other ways to Give
 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A127818 a(n) is the least k such that the remainder when 10^k is divided by k is n. 38
 3, 14, 7, 6, 35, 94, 993, 46, 22963573117, 11, 15084115509707, 22, 21, 86, 99985, 24, 221819, 82, 327, 1996, 28039, 26, 169, 38, 39, 74, 24257, 36, 10191082613, 65, 49, 34, 4739, 66, 99965, 188, 171, 62, 3753219157, 60, 3961, 58, 87, 76, 28315, 159, 10441 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS a(9) <= 22963573117 from Joe K. Crump (joecr(AT)carolina.rr.com), Feb 09 2007 a(11) <= 15084115509707 from Joe K. Crump (joecr(AT)carolina.rr.com), Feb 06 2007 a(29) <= 112237795073 from Joe K. Crump (joecr(AT)carolina.rr.com), Feb 09 2007 a(39) <= 3753219157 from Joe K. Crump (joecr(AT)carolina.rr.com), Feb 10 2007 LINKS MATHEMATICA t = Table[0, {10000} ]; k = 1; While[ k < 4000000000, a = PowerMod[10, k, k]; If[a < 10001 && t[[a]] == 0, t[[a]] = k; Print[{a, k}]]; k++ ]; t PROG (Python) def a(n): k = 1 while 10**k % k != n: k += 1 return k print([a(n) for n in range(1, 9)]) # Michael S. Branicky, Mar 14 2021 CROSSREFS Cf. A036236, A078457, A119678, A119679, A127816, A119715, A119714, A127817, A127819, A127820, A127821. Sequence in context: A341860 A197423 A090786 * A320261 A344116 A187772 Adjacent sequences: A127815 A127816 A127817 * A127819 A127820 A127821 KEYWORD hard,nonn AUTHOR Alexander Adamchuk, Jan 30 2007 EXTENSIONS Crump's values for a(9), a(11), a(39) confirmed, a(29) = 10191082613 = 16763 * 607951 by Hagen von Eitzen, Jul 29 2009 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified December 7 01:51 EST 2022. Contains 358649 sequences. (Running on oeis4.)