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 A037597 Base-4 digits are, in order, the first n terms of the periodic sequence with initial period 1,3,0. 2
 1, 7, 28, 113, 455, 1820, 7281, 29127, 116508, 466033, 1864135, 7456540, 29826161, 119304647, 477218588, 1908874353, 7635497415, 30541989660, 122167958641, 488671834567, 1954687338268, 7818749353073, 31274997412295 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 LINKS Vincenzo Librandi, Table of n, a(n) for n = 1..300 Index entries for linear recurrences with constant coefficients, signature (4,0,1,-4). FORMULA a(n) = floor(4^(n+1)/9). [Mircea Merca, Dec 26 2010] G.f.: x*(1+3*x) / ( (x-1)*(4*x-1)*(1+x+x^2) ). [Joerg Arndt, Jan 08 2011] a(n) = 4*a(n-1) + a(n-3) - 4*a(n-4). [Joerg Arndt, Jan 08 2011] a(1)=1, a(2)=7, a(n) = 5*a(n-1) - 4*a(n-2) + (period 3: repeat -3, 1, 2); a(n) = 4*a(n) +1 + (period 3: repeat 0, 1, 3). [Vincenzo Librandi, Jun 06 2011] MAPLE seq(floor(4^(n+1)/9), n=1..32); # Mircea Merca, Dec 28 2010 PROG (Magma) [Floor(4^(n+1)/9): n in [1..30]]; // Vincenzo Librandi, May 22 2011 (PARI) a(n)=4^(n+1)\9 \\ Charles R Greathouse IV, Jun 06 2011 CROSSREFS Cf. A178744. Sequence in context: A002042 A200666 A207098 * A037702 A359018 A302523 Adjacent sequences: A037594 A037595 A037596 * A037598 A037599 A037600 KEYWORD nonn,base,easy AUTHOR Clark Kimberling STATUS approved

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Last modified October 1 14:54 EDT 2023. Contains 365826 sequences. (Running on oeis4.)