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 A111575 Powers of 3 repeated four times. 7
 1, 1, 1, 1, 3, 3, 3, 3, 9, 9, 9, 9, 27, 27, 27, 27, 81, 81, 81, 81, 243, 243, 243, 243, 729, 729, 729, 729, 2187, 2187, 2187, 2187, 6561, 6561, 6561, 6561, 19683, 19683, 19683, 19683, 59049, 59049, 59049, 59049, 177147, 177147, 177147, 177147, 531441 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,5 COMMENTS Generating sequence for the number of 0's and 1's (run lengths) in the parity of A006072, A111065 and A118594. LINKS Vincenzo Librandi, Table of n, a(n) for n = 0..8000 FORMULA a(n) = 3^floor(n/4). O.g.f.: -(1+x)*(1+x^2)/(-1+3*x^4). - R. J. Mathar, Jan 08 2008 EXAMPLE a(10) = 3^floor(10/4) = 3^2 = 9. MATHEMATICA With[{pt=3^Range[0, 15]}, Sort[Join[pt, pt, pt, pt]]] (* Harvey P. Dale, Sep 17 2011 *) Table[PadRight[{}, 4, 3^n], {n, 0, 15}]//Flatten (* Harvey P. Dale, Jan 17 2019 *) PROG (MAGMA) [3^(Floor(n/4)):n in [0..50]]; // Vincenzo Librandi, Sep 20 2011 (PARI) a(n)=3^(n\4) \\ Charles R Greathouse IV, Oct 03 2016 CROSSREFS Cf. A006072, A111065, A108411, A118594, A127975. Sequence in context: A184099 A074816 A203564 * A161836 A087576 A337328 Adjacent sequences:  A111572 A111573 A111574 * A111576 A111577 A111578 KEYWORD nonn,easy AUTHOR Jeremy Gardiner, Nov 17 2005 STATUS approved

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Last modified October 25 01:18 EDT 2020. Contains 338010 sequences. (Running on oeis4.)