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Search: id:A141534
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| A141534 |
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Derived from the centered polygonal numbers: start with the first triangular number, then the sum of the first square number and the second triangular number, then the sum of first pentagonal number, the second square number and the third triangular number and so on and so on... |
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+0
1
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| 1, 4, 11, 26, 55, 105, 184, 301, 466, 690, 985, 1364, 1841, 2431, 3150, 4015, 5044, 6256, 7671
(list; graph; listen)
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OFFSET
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1,2
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COMMENT
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For comparison, the antidiagonal sums of A086270 are essentially A006522 starting at the 4th term. [From R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Sep 20 2008]
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FORMULA
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Conjecture: a(n)=(n-1)(n^3+11n^2-38n+120)/24, n>1. [From R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Sep 12 2008]
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CROSSREFS
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Cf. A000217.
Sequence in context: A076048 A109414 A027966 this_sequence A027660 A002940 A030196
Adjacent sequences: A141531 A141532 A141533 this_sequence A141535 A141536 A141537
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KEYWORD
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nonn,more
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AUTHOR
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Dan Graybill (clopen(AT)comcast.net), Aug 12 2008
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