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 A168328 a(n) = 6 * floor( n/2 ). 2
 0, 6, 6, 12, 12, 18, 18, 24, 24, 30, 30, 36, 36, 42, 42, 48, 48, 54, 54, 60, 60, 66, 66, 72, 72, 78, 78, 84, 84, 90, 90, 96, 96, 102, 102, 108, 108, 114, 114, 120, 120, 126, 126, 132, 132, 138, 138, 144, 144, 150, 150, 156, 156, 162, 162, 168, 168, 174, 174, 180, 180 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 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) = 6*n - a(n-1) - 6 for n>1, a(1)=0. G.f.: 6*x^2/((1+x)*(1-x)^2). - Bruno Berselli, Sep 17 2013 a(n) = 6*A004526(n). Bruno Berselli, Sep 17 2013 E.g.f.: 3*(x*cosh(x) + (x - 1)*sinh(x)). - G. C. Greubel, Jul 18 2016 MATHEMATICA Table[6 Floor[n/2], {n, 70}] (* Bruno Berselli, Sep 18 2013 *) PROG (MAGMA) [n eq 1 select 0 else 6*n-Self(n-1)-6: n in [1..70]]; // Vincenzo Librandi, Sep 17 2013 CROSSREFS Cf. A004526, A008588. Sequence in context: A028317 A220435 A055665 * A176569 A315778 A315779 Adjacent sequences:  A168325 A168326 A168327 * A168329 A168330 A168331 KEYWORD nonn,easy,less AUTHOR Vincenzo Librandi, Nov 23 2009 EXTENSIONS G.f. adapted to the offset by Vincenzo Librandi, Sep 17 2013 New definition by Bruno Berselli, Sep 18 2013 STATUS approved

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Last modified August 24 03:51 EDT 2019. Contains 326260 sequences. (Running on oeis4.)