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A352975
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a(n) is the smallest number which can be represented as the sum of n distinct centered n-gonal numbers in exactly n ways, or -1 if no such number exists.
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0
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96, 192, 330, 504, 840, 1304, 1872, 2910, 3971, 5340, 6851, 8932, 11700, 14496, 18258, 22410, 27265, 32620, 39606, 47124, 55545, 65448, 76050, 87854, 101925, 116956, 134125, 152340, 173538, 195424, 220473, 246942, 276570, 306756, 340918, 377644, 418821, 462720
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OFFSET
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3,1
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COMMENTS
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If a(n) exists, then n divides a(n). - Thomas Scheuerle, Apr 13 2022
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LINKS
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Table of n, a(n) for n=3..40.
Eric Weisstein's World of Mathematics, Centered Polygonal Number
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FORMULA
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a(n) >= n*binomial(n + 2, 3) + n, if a(n) does exist. - Thomas Scheuerle, Apr 13 2022
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EXAMPLE
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For n = 3: 96 = 1 + 10 + 85 = 1 + 31 + 64 = 19 + 31 + 46.
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CROSSREFS
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Cf. A101321, A350209, A350397, A350405.
Sequence in context: A090762 A206337 A161482 * A044428 A044809 A115437
Adjacent sequences: A352972 A352973 A352974 * A352976 A352977 A352978
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KEYWORD
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nonn
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AUTHOR
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Ilya Gutkovskiy, Apr 13 2022
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EXTENSIONS
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a(10)-a(16) from Thomas Scheuerle, Apr 13 2022
a(17)-a(40) from Michael S. Branicky, May 19 2022
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STATUS
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approved
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