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A036520
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Smallest triangular number containing exactly n 3's.
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1
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3, 3003, 33153, 3303735, 333336, 333039336, 13333363350, 330335331336, 3033333513330, 303313733373336, 30333330330333465, 313631353332333336, 330332337333331336, 3333043333303433331, 3333333330453337336653, 30733333373333335323321, 330332334339335333331336, 33033333933433336339893330
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OFFSET
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1,1
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LINKS
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Table of n, a(n) for n=1..18.
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MATHEMATICA
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nsmall = Table[Infinity, 20];
For[i = 0, i <= 10^6, i++, p = PolygonalNumber[i];
n0 = Count[IntegerDigits[p], 3];
If[nsmall[[n0]] > p, nsmall[[n0]] = p]];
ReplaceAll[nsmall, Infinity -> "?"] (* Robert Price, Mar 22 2020 *)
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CROSSREFS
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Cf. A048358, A036517-A036526.
Sequence in context: A003534 A202520 A281928 * A359130 A193447 A134909
Adjacent sequences: A036517 A036518 A036519 * A036521 A036522 A036523
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KEYWORD
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nonn,base
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AUTHOR
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David W. Wilson
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EXTENSIONS
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a(12)-a(18) from Giovanni Resta, Oct 30 2019
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STATUS
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approved
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