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A069172
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Smallest triangular number such that arithmetic mean of its digits = n (sum of the digits = n times the number of digits).
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0
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OFFSET
| 1,2
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COMMENTS
| a(9) > 10^100000 if it exists. a(9) must be of the form 10^x-1. [From Donovan Johnson (donovan.johnson(AT)yahoo.com), Mar 30 2010]
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MATHEMATICA
| Do[k = 1; While[ Apply[ Plus, IntegerDigits[k(k + 1)/2]] != n*Floor[ Log[10, k(k + 1)/2] + 1], k++ ]; Print[k(k + 1)/2], {n, 1, 7}]
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CROSSREFS
| Cf. A069790.
Sequence in context: A048920 A091539 A157874 * A104437 A112814 A058179
Adjacent sequences: A069169 A069170 A069171 * A069173 A069174 A069175
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KEYWORD
| base,fini,nonn
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AUTHOR
| Robert G. Wilson v (rgwv(AT)rgwv.com), Apr 09 2002
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EXTENSIONS
| a(8) from Donovan Johnson (donovan.johnson(AT)yahoo.com), Mar 30 2010
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