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Search: id:A087345
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| A087345 |
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Smallest prime which is a concatenation of n successive triangular numbers, or 0 if no such number exists. |
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+0
2
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| 3, 0, 210231253, 171190210231, 36101521, 136101521, 1596165317111770183018911953, 105120136153171190210231, 0, 17020172051739117578177661795518145183361852818721
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OFFSET
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1,1
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COMMENT
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a(9k) = 0 because the concatenation of 9k successive triangular numbers is always divisible by 3. - David Wasserman (wasserma(AT)spawar.navy.mil), May 10 2005
Erroneous version of A105291. a(2)=13 is a concatenation of 2 consecutive triangular numbers (namely 1 and 3). [From R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Dec 13 2008]
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EXAMPLE
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a(3) = concatenation of 210, 231 and 253, three successive triangular numbers.
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CROSSREFS
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Cf. A087344.
Sequence in context: A076951 A060282 A060283 this_sequence A140334 A078529 A121383
Adjacent sequences: A087342 A087343 A087344 this_sequence A087346 A087347 A087348
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KEYWORD
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base,nonn
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AUTHOR
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Amarnath Murthy (amarnath_murthy(AT)yahoo.com), Sep 06 2003
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EXTENSIONS
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More terms from David Wasserman (wasserma(AT)spawar.navy.mil), May 10 2005
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