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 A168332 a(n) = 6 + 7 * floor((n-1)/2). 2
 6, 6, 13, 13, 20, 20, 27, 27, 34, 34, 41, 41, 48, 48, 55, 55, 62, 62, 69, 69, 76, 76, 83, 83, 90, 90, 97, 97, 104, 104, 111, 111, 118, 118, 125, 125, 132, 132, 139, 139, 146, 146, 153, 153, 160, 160, 167, 167, 174, 174, 181, 181, 188, 188, 195, 195, 202, 202, 209 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS Vincenzo Librandi, Table of n, a(n) for n = 1..1000 Index entries for linear recurrences with constant coefficients, signature (1,1,-1). FORMULA a(n) = 7*n - a(n-1) - 2, with n>1, a(1)=6. G.f.: x*(6 + x^2)/((1+x)*(x-1)^2). - Vincenzo Librandi, Sep 17 2013 a(n) = a(n-1) +a(n-2) -a(n-3). - Vincenzo Librandi, Sep 17 2013 a(n) = (14*n - 7*(-1)^n + 3)/4 = A168374(n+1) - 1 = A168336(n) + 1. - Bruno Berselli, Sep 17 2013 E.g.f.: (1/2)*(2 + (7*x - 2)*cosh(x) + (7*x + 5)*sinh(x)). - G. C. Greubel, Jul 18 2016 MATHEMATICA Table[6 + 7 Floor[(n - 1)/2], {n, 60}] (* Bruno Berselli, Sep 17 2013 *) CoefficientList[Series[(6 + x^2)/((1 + x) (x - 1)^2), {x, 0, 70}], x] (* Vincenzo Librandi, Sep 17 2013 *) LinearRecurrence[{1, 1, -1}, {6, 6, 13}, 60] (* or *) With[{c=NestList[ #+7&, 6, 30]}, Riffle[c, c]] (* Harvey P. Dale, Aug 29 2015 *) PROG (MAGMA) [n eq 1 select 6 else 7*n-Self(n-1)-2: n in [1..70]]; // Vincenzo Librandi, Sep 17 2013 CROSSREFS Cf. A168336, A168374. Sequence in context: A262850 A262849 A115014 * A214828 A229828 A141378 Adjacent sequences:  A168329 A168330 A168331 * A168333 A168334 A168335 KEYWORD nonn,easy AUTHOR Vincenzo Librandi, Nov 23 2009 EXTENSIONS Definition reformulated by Bruno Berselli at the suggestion of Joerg Arndt and using its formula, Sep 17 2013 STATUS approved

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Last modified July 1 06:48 EDT 2022. Contains 354952 sequences. (Running on oeis4.)