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 A166450 a(n) = 3*a(n-2) for n > 2; a(1) = 1, a(2) = 6. 1
 1, 6, 3, 18, 9, 54, 27, 162, 81, 486, 243, 1458, 729, 4374, 2187, 13122, 6561, 39366, 19683, 118098, 59049, 354294, 177147, 1062882, 531441, 3188646, 1594323, 9565938, 4782969, 28697814, 14348907, 86093442, 43046721, 258280326 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Interleaving of A000244 and 6*A000244. Second binomial transform is A055845. Sixth binomial transform is A153597. LINKS Vincenzo Librandi, Table of n, a(n) for n = 1..1000 Index entries for linear recurrences with constant coefficients, signature (0,3). FORMULA a(n) = (3+(-1)^n)*3^(1/4*(2*n-1+(-1)^n))/2. G.f.: x*(1+6*x)/(1-3*x^2). MATHEMATICA LinearRecurrence[{0, 3}, {1, 6}, 50] (* G. C. Greubel, May 14 2016 *) PROG (MAGMA) [ n le 2 select 5*n-4 else 3*Self(n-2): n in [1..35] ]; CROSSREFS Cf. A000244 (powers of 3), A055845, A153597. Sequence in context: A067990 A174012 A050008 * A019069 A213752 A134410 Adjacent sequences:  A166447 A166448 A166449 * A166451 A166452 A166453 KEYWORD nonn,easy AUTHOR Klaus Brockhaus, Oct 13 2009 STATUS approved

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Last modified June 18 07:25 EDT 2021. Contains 345098 sequences. (Running on oeis4.)