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A101170
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a(n) divides the number formed by concatenating the sum of the digits of a(n) with a(n).
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1
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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; internal format)
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OFFSET
| 1,2
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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 (maxale(AT)gmail.com), May 08 2009]
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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.
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CROSSREFS
| Cf. A101171.
Sequence in context: A036965 A133184 A102576 * A130224 A017903 A005711
Adjacent sequences: A101167 A101168 A101169 * A101171 A101172 A101173
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KEYWORD
| base,nonn
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AUTHOR
| Chuck Seggelin (seqfan(AT)plastereddragon.com), Dec 03 2004
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