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Search: id:A027696
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| A027696 |
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Nonparametric solutions to problem in A027669: n such that for some m, the sum of the first m n-gonal numbers is again an n-gonal number. |
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+0
2
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| 3, 4, 6, 8, 10, 11, 14, 17, 30, 41, 43, 50, 60, 88, 145, 276, 322, 374, 823, 1152
(list; graph; listen)
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OFFSET
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0,1
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FORMULA
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The parametric solution: if n=2 mod 3, the sum of the first (n^2-4*n-2)/3 n-gonal numbers is an ((n^3-6*n^2+3*n+19)/9 th) n-gonal number.
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CROSSREFS
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Cf. A027669.
Sequence in context: A091555 A024665 A027669 this_sequence A027440 A029902 A024511
Adjacent sequences: A027693 A027694 A027695 this_sequence A027697 A027698 A027699
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KEYWORD
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nonn
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AUTHOR
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Masanobu Kaneko (mkaneko(AT)math.kyushu-u.ac.jp)
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EXTENSIONS
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Extended Jan 05 1998 by Masanobu Kaneko.
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