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A068129
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Triangular numbers with sum of digits = 10.
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5
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28, 55, 91, 136, 190, 253, 325, 406, 703, 820, 1081, 1225, 1540, 1711, 2080, 2701, 3160, 3403, 5050, 7021, 10153, 11026, 12403, 15400, 17020, 20503, 21115, 23005, 24310, 32131, 41041, 51040, 52003, 60031, 72010, 80200, 90100, 106030, 110215
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,1
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COMMENTS
| 1. The sequence is unbounded, as the (2*10^k +2)-th triangular number is a term. 2. The sum of the digits of triangular numbers in most cases is a triangular number. 3. Conjecture: For every triangular number T there exist infinitely many triangular numbers with sum of digits = T.
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CROSSREFS
| Cf. A068127, A068128.
Sequence in context: A044461 A056028 A120372 * A079731 A119168 A040756
Adjacent sequences: A068126 A068127 A068128 * A068130 A068131 A068132
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KEYWORD
| base,easy,nonn
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AUTHOR
| Amarnath Murthy (amarnath_murthy(AT)yahoo.com), Feb 21 2002
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EXTENSIONS
| More terms from Sascha Kurz (sascha.kurz(AT)uni-bayreuth.de), Mar 06 2002
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