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Search: id:A069126
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| A069126 |
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Centered 13-gonal numbers. |
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+0
6
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| 1, 14, 40, 79, 131, 196, 274, 365, 469, 586, 716, 859, 1015, 1184, 1366, 1561, 1769, 1990, 2224, 2471, 2731, 3004, 3290, 3589, 3901, 4226, 4564, 4915, 5279, 5656
(list; graph; listen)
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OFFSET
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1,2
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LINKS
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E. Weisstein, Centered Polygonal Numbers
Index entries for sequences related to centered polygonal numbers
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FORMULA
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a(n) = (13n^2 - 13n + 2)/2
Binomial transform of [1, 13, 13, 0, 0, 0,...]; Narayana transform (A001263) of [1, 13, 0, 0, 0,...]. - Gary W. Adamson (qntmpkt(AT)yahoo.com), Dec 29 2007
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EXAMPLE
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a(5) = 131 because 131 = (13*5^2 - 13*5 + 2)/2 = (325 - 65 + 2)/2 = 262/2 = 131
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CROSSREFS
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Cf. A005448, A001844, A005891, A003215, A069099.
Cf. A001263.
Sequence in context: A051866 A019063 A101740 this_sequence A124707 A126368 A125816
Adjacent sequences: A069123 A069124 A069125 this_sequence A069127 A069128 A069129
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KEYWORD
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easy,nice,nonn
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AUTHOR
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Terrel Trotter, Jr. (ttrotter(AT)telesal.net), Apr 07 2002
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