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 A169721 a(n) = (2*(3*2^(n-1)-1))^2. 3
 1, 16, 100, 484, 2116, 8836, 36100, 145924, 586756, 2353156, 9424900, 37724164, 150945796, 603881476, 2415722500, 9663283204, 38653919236, 154617249796, 618472144900, 2473894871044, 9895592067076, 39582393434116, 158329624068100, 633318596935684 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 COMMENTS A subsequence of the squares (A000290). LINKS Vincenzo Librandi, Table of n, a(n) for n = 0..1000 Alice V. Kleeva, Grid for this sequence Alice V. Kleeva, Illustration of initial terms Robert Munafo, Sequence A169720, and two others by Alice V. Kleeva Robert Munafo, Sequence A169720, and two others by Alice V. Kleeva [Cached copy, in pdf format, included with permission] Index entries for linear recurrences with constant coefficients, signature (7,-14,8). FORMULA a(n) = A033484(n)^2. G.f.: (1+9*x+2*x^2)/(1-7*x+14*x^2-8*x^3). - Bruno Berselli, Dec 04 2012 a(n) = 7*a(n-1)-14*a(n-2)+8*a(n-3). - Vincenzo Librandi, Dec 04 2012 MATHEMATICA Table[(2(3*2^(n-1)-1))^2, {n, 0, 30}] (* Harvey P. Dale, Oct 29 2012 *) CoefficientList[Series[(1+x)/((1-x)*(1-2*x)), {x, 0, 30}], x]^2 (* Vincenzo Librandi, Dec 04 2012 *) PROG (MAGMA) I:=[1, 16, 100]; [n le 3 select I[n] else 7*Self(n-1)-14*Self(n-2)+8*Self(n-3): n in [1..30]]; // Vincenzo Librandi, Dec 04 2012 CROSSREFS Cf. A169720-A169727. Sequence in context: A001249 A014796 A052206 * A125326 A126484 A091100 Adjacent sequences:  A169718 A169719 A169720 * A169722 A169723 A169724 KEYWORD nonn,easy AUTHOR Alice V. Kleeva (alice27353(AT)gmail.com), Jan 19 2010 STATUS approved

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Last modified April 22 07:15 EDT 2021. Contains 343162 sequences. (Running on oeis4.)