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 A143855 Ulam's spiral (ESE spoke). 2
 1, 10, 51, 124, 229, 366, 535, 736, 969, 1234, 1531, 1860, 2221, 2614, 3039, 3496, 3985, 4506, 5059, 5644, 6261, 6910, 7591, 8304, 9049, 9826, 10635, 11476, 12349, 13254, 14191, 15160, 16161, 17194, 18259, 19356, 20485, 21646, 22839, 24064 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Also sequence found by reading the segment (1, 10) together with the line from 10, in the direction 10, 51, ..., in the square spiral whose vertices are the generalized decagonal numbers A074377. - Omar E. Pol, Nov 05 2012 LINKS Index entries for linear recurrences with constant coefficients, signature (3,-3,1). FORMULA a(n) = 16n^2-39n+24. - R. J. Mathar, Sep 08 2008 G.f.: x*(1+7*x+24*x^2)/(1-x)^3. - Colin Barker, Aug 03 2012 MATHEMATICA f[n_] := 16n^2 -39n +24; Array[f, 40] (* Vladimir Joseph Stephan Orlovsky, Sep 04 2008 *) CoefficientList[Series[(1 + 7 x + 24 x^2) / (1 - x)^3, {x, 0, 40}], x] (* Vincenzo Librandi, Nov 08 2014 *) PROG (MAGMA) [16*n^2-39*n+24: n in [1..50]]; // Vincenzo Librandi, Nov 08 2014 (PARI) vector(50, n, 16*n^2-39*n+24) \\ Michel Marcus, Nov 08 2014 CROSSREFS Sequence in context: A143558 A106041 A264044 * A124162 A077044 A069038 Adjacent sequences:  A143852 A143853 A143854 * A143856 A143857 A143858 KEYWORD nonn,easy AUTHOR Vladimir Joseph Stephan Orlovsky, Sep 03 2008, Sep 04 2008 STATUS approved

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Last modified August 17 11:14 EDT 2019. Contains 326057 sequences. (Running on oeis4.)