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Search: id:A068133
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| A068133 |
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First triangular number with digit sum = n-th triangular number. |
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+0
2
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| 1, 3, 6, 28, 78, 1596, 5995, 67896, 887778, 15997996, 398988876, 9876799878, 299789989975, 35998897988976, 589598998999878, 78999997699698778, 7987899888859999878
(list; graph; listen)
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OFFSET
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0,2
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COMMENT
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The sum of the digits of triangular numbers in most cases is a triangular number. Conjecture: For every triangular number T there exist infinitely many triangular numbers with sum of digits = T.
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CROSSREFS
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Cf. A068127, A068128, A068129, A068130, A068131, A068132, A068133.
Sequence in context: A102428 A128056 A068808 this_sequence A024497 A007228 A096155
Adjacent sequences: A068130 A068131 A068132 this_sequence A068134 A068135 A068136
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KEYWORD
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base,more,nonn
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AUTHOR
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Amarnath Murthy (amarnath_murthy(AT)yahoo.com), Feb 21 2002
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EXTENSIONS
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More terms from Larry Reeves (larryr(AT)acm.org), Jun 17 2002
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