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A098923
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33-gonal numbers: n(31n-29)/2.
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4
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0, 1, 33, 96, 190, 315, 471, 658, 876, 1125, 1405, 1716, 2058, 2431, 2835, 3270, 3736, 4233, 4761, 5320, 5910, 6531, 7183, 7866, 8580, 9325, 10101, 10908, 11746, 12615, 13515, 14446, 15408, 16401, 17425, 18480, 19566, 20683, 21831, 23010
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,3
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COMMENTS
| Similar to 21-gonal and 15-gonal numbers.
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LINKS
| Index to sequences with linear recurrences with constant coefficients, signature (3,-3,1).
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FORMULA
| a(n) = n(31n-29)/2.
G.f.: x*(1+30*x)/(1-x)^3. - Bruno Berselli, Feb 04 2011
a(n)=31*n+a(n-1)-30 (with a(0)=0) [From Vincenzo Librandi, Nov 16 2010]
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MATHEMATICA
| Table[n(31n - 29)/2, {n, 0, 40}] - Stefan Steinerberger (stefan.steinerberger(AT)gmail.com), Feb 15 2006
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CROSSREFS
| Cf. n-gonal numbers A000217, A000290, A000326, A000566, A000567, A001106, A001107, A051682, A051624, A051865-A051876, A098924, A098140, A098230.
Sequence in context: A114069 A165378 A098938 * A044220 A044601 A195315
Adjacent sequences: A098920 A098921 A098922 * A098924 A098925 A098926
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KEYWORD
| nonn,easy
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AUTHOR
| Parthasarathy Nambi (PachaNambi(AT)yahoo.com), Oct 18 2004
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EXTENSIONS
| More terms from Stefan Steinerberger (stefan.steinerberger(AT)gmail.com), Feb 15 2006
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