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 A070875 Binary expansion is 1x100...0 where x = 0 or 1. 5
 5, 7, 10, 14, 20, 28, 40, 56, 80, 112, 160, 224, 320, 448, 640, 896, 1280, 1792, 2560, 3584, 5120, 7168, 10240, 14336, 20480, 28672, 40960, 57344, 81920, 114688, 163840, 229376, 327680, 458752, 655360, 917504, 1310720, 1835008, 2621440 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,1 COMMENTS A093873(a(n)) = 2. - Reinhard Zumkeller, Oct 13 2006 For n>1 we have a(n+1) = a(n) + phi(a(n)) where phi is A000010. - Stefan Steinerberger, Dec 20 2007 A 2-automatic sequence. - Charles R Greathouse IV, Sep 24 2012 LINKS FORMULA Contribution by Bruno Berselli, Mar 01 2011: (Start) G.f.: (5+7*x)/(1-2*x^2). a(n) = (6-(-1)^n)*2^((2*n+(-1)^n-1)/4). Therefore: a(n) = 5*2^(n/2) for n even, otherwise a(n) = 7*2^((n-1)/2). a(n) = 2*a(n-2) for n>1. (End) a(n+1) = A063757(n) + 6. - Philippe Deléham, Apr 13 2013 MATHEMATICA Flatten@ NestList[ 2# &, {5, 7}, 19] (* Or *) CoefficientList[ Series[(5 + 7 x)/(1 - 2 x^2), {x, 0, 38}], x] (* Robert G. Wilson v *) PROG (MAGMA) [n le 2 select 2*n+3 else 2*Self(n-2): n in [1..39]]; // Bruno Berselli, mar 01 2011 (PARI) a(n)=if(n%2, 7, 5)<<(n\2) \\ Charles R Greathouse IV, Sep 24 2012 CROSSREFS Cf. A070876, A123760. Sequence in context: A020942 A190035 A071911 * A091522 A020711 A183044 Adjacent sequences:  A070872 A070873 A070874 * A070876 A070877 A070878 KEYWORD nonn,easy AUTHOR N. J. A. Sloane, May 19 2002 EXTENSIONS Extended by Robert G. Wilson v, May 20 2002 STATUS approved

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