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 A195145 Concentric 14-gonal numbers. 14
 0, 1, 14, 29, 56, 85, 126, 169, 224, 281, 350, 421, 504, 589, 686, 785, 896, 1009, 1134, 1261, 1400, 1541, 1694, 1849, 2016, 2185, 2366, 2549, 2744, 2941, 3150, 3361, 3584, 3809, 4046, 4285, 4536, 4789, 5054, 5321, 5600, 5881, 6174, 6469, 6776, 7085, 7406 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,3 COMMENTS Also concentric tetradecagonal numbers or concentric tetrakaidecagonal numbers. Also sequence found by reading the line from 0, in the direction 0, 14, ..., and the same line from 1, in the direction 1, 29, ..., in the square spiral whose vertices are the generalized enneagonal numbers A118277. Main axis, perpendicular to A024966 in the same spiral. Partial sums of A113801. - Reinhard Zumkeller, Jan 07 2012 LINKS Vincenzo Librandi, Table of n, a(n) for n = 0..10000 Index entries for linear recurrences with constant coefficients, signature (2,0,-2,1). FORMULA G.f.: -x*(1+12*x+x^2) / ( (1+x)*(x-1)^3 ). - R. J. Mathar, Sep 18 2011 From Vincenzo Librandi, Sep 27 2011: (Start) a(n) = (14*n^2 + 5*(-1)^n - 5)/4; a(n) = a(-n) = -a(n-1) + 7*n^2 - 7*n + 1. (End) PROG (MAGMA) [(14*n^2+5*(-1)^n-5)/4: n in [0..50]]; // Vincenzo Librandi, Sep 27 2011 (Haskell) a195145 n = a195145_list !! n a195145_list = scanl (+) 0 a113801_list -- Reinhard Zumkeller, Jan 07 2012 CROSSREFS Cf. A144555 and A195314 interleaved. Cf. A032527, A032528, A077221, A195045, A195046, A195142, A195143, A195146, A195147, A195148, A195149. Column 14 of A195040. - Omar E. Pol, Sep 28 2011 Sequence in context: A132756 A192836 A124681 * A263119 A196305 A041386 Adjacent sequences:  A195142 A195143 A195144 * A195146 A195147 A195148 KEYWORD nonn,easy AUTHOR Omar E. Pol, Sep 17 2011 STATUS approved

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Last modified October 19 04:40 EDT 2019. Contains 328211 sequences. (Running on oeis4.)