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 A156773 a(n) = 6561*n^2 - 9558*n + 3482. 3
 3482, 485, 10610, 33857, 70226, 119717, 182330, 258065, 346922, 448901, 564002, 692225, 833570, 988037, 1155626, 1336337, 1530170, 1737125, 1957202, 2190401, 2436722, 2696165, 2968730, 3254417, 3553226, 3865157, 4190210, 4528385 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,1 COMMENTS The identity (6561*n^2 - 9558*n + 3482)^2 - (81*n^2 - 118*n + 43)*(729*n - 531)^2 = 1 can be written as a(n)^2 - A156677(n)*A156771(n)^2 = 1 for n>0. [rewritten by Bruno Berselli, Jul 21 2011] LINKS Vincenzo Librandi, Table of n, a(n) for n = 0..10000 Index entries for linear recurrences with constant coefficients, signature (3,-3,1). FORMULA G.f.: (3482 - 9961*x + 19601*x^2)/(1-x)^3. - Colin Barker, Jan 09 2012 E.g.f.: (3482 - 2997*x + 6561*x^2)*exp(x). - G. C. Greubel, Jun 21 2021 a(n) = 3*a(n-1) - 3*a(n-2) + a(n-3). - Wesley Ivan Hurt, Sep 03 2022 MATHEMATICA Table[6561n^2-9558n+3482, {n, 0, 30}] (* Harvey P. Dale, Apr 06 2011 *) PROG (Magma) [6561*n^2-9558*n+3482: n in [0..35]]; (PARI) a(n)=6561*n^2-9558*n+3482 \\ Charles R Greathouse IV, Dec 23 2011 (Sage) [3482 -9558*n +6561*n^2 for n in (0..35)] # G. C. Greubel, Jun 21 2021 CROSSREFS Cf. A156677, A156771. Sequence in context: A328817 A159215 A176380 * A174753 A031557 A031737 Adjacent sequences: A156770 A156771 A156772 * A156774 A156775 A156776 KEYWORD nonn,easy AUTHOR Vincenzo Librandi, Feb 15 2009 EXTENSIONS Checked by Michael B. Porter, Jun 16 2010 Offset corrected by N. J. A. Sloane, Jun 22 2010 STATUS approved

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Last modified March 31 00:51 EDT 2023. Contains 361623 sequences. (Running on oeis4.)