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 A101170 a(n) divides the number formed by concatenating the sum of the digits of a(n) with a(n). 1
 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 15, 18, 20, 24, 25, 30, 36, 40, 45, 48, 50, 60, 70, 75, 80, 90, 100, 120, 125, 150, 180, 200, 225, 240, 250, 300, 360, 375, 400, 450, 480, 500, 600, 700, 750, 800, 900, 1000, 1125, 1200, 1250, 1500, 1800, 1875, 2000, 2250, 2400, 2500 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS The most common factor is 11, which catches most of the trivial cases such as 5000 (which when concatenated with its digit sum yields 55000... 11 * 5000). See A101171 for the first sequence member which uses a new factor. There are only a finite number of terms ending with a nonzero digit. See A101171 for the proof. [From Max Alekseyev, May 08 2009] LINKS EXAMPLE a(50)=1125 because the number formed by concatenating the digit sum of 1125 (9) with 1125 yields a number (91125) that 1125 evenly divides. 91125 / 1125 = 81. CROSSREFS Cf. A101171. Sequence in context: A036965 A133184 A102576 * A236686 A246084 A260768 Adjacent sequences:  A101167 A101168 A101169 * A101171 A101172 A101173 KEYWORD base,nonn AUTHOR Chuck Seggelin (seqfan(AT)plastereddragon.com), Dec 03 2004 STATUS approved

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Last modified September 22 22:24 EDT 2020. Contains 337291 sequences. (Running on oeis4.)