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A051869
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17-gonal (or heptadecagonal) numbers: n(15n-13)/2.
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9
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0, 1, 17, 48, 94, 155, 231, 322, 428, 549, 685, 836, 1002, 1183, 1379, 1590, 1816, 2057, 2313, 2584, 2870, 3171, 3487, 3818, 4164, 4525, 4901, 5292, 5698, 6119, 6555, 7006, 7472, 7953, 8449, 8960, 9486, 10027, 10583, 11154, 11740, 12341
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OFFSET
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0,3
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COMMENTS
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Sequence found by reading the line from 0, in the direction 0, 17,... and the parallel line from 1, in the direction 1, 48,..., in the square spiral whose vertices are the generalized 17-gonal numbers. - Omar E. Pol, Jul 18 2012
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REFERENCES
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A. H. Beiler, Recreations in the Theory of Numbers, Dover, N.Y., 1964, p. 189.
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LINKS
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Table of n, a(n) for n=0..41.
Index to sequences with linear recurrences with constant coefficients, signature (3,-3,1).
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FORMULA
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a(n)=n(15n-13)/2.
G.f.: x*(1+14*x)/(1-x)^3. - Bruno Berselli, Feb 04 2011
a(n)=15*n+a(n-1)-14 (with a(0)=0) [From Vincenzo Librandi, Aug 06 2010]
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EXAMPLE
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a(1)=15*1+0-14=1; a(2)=15*2+1-14=17; a(3)=15*3+17-14=48 [From Vincenzo Librandi, Aug 06 2010]
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MAPLE
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A051869 := proc(n) n*(15*n-13)/2 ; end proc: seq(A051869(n), n=0..30) ; # R. J. Mathar, Feb 05 2011
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MATHEMATICA
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s=0; lst={s}; Do[s+=n++ +1; AppendTo[lst, s], {n, 0, 6!, 15}]; lst [From Vladimir Joseph Stephan Orlovsky, Nov 16 2008]
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CROSSREFS
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Cf. A002378.
Cf. n-gonal numbers: A000217, A000290, A000326, A000384, A000566, A000567, A001106, A001107, A051682, A051624, A051865-A051868, this sequence, A051870-A051876.
Sequence in context: A083296 A159850 A031122 * A210372 A181426 A029487
Adjacent sequences: A051866 A051867 A051868 * A051870 A051871 A051872
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KEYWORD
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nonn
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AUTHOR
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N. J. A. Sloane, Dec 15 1999
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STATUS
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approved
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