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 A173873 a(n) = 2*a(n-1) + 13, a(1)=1. 1
 1, 15, 43, 99, 211, 435, 883, 1779, 3571, 7155, 14323, 28659, 57331, 114675, 229363, 458739, 917491, 1834995, 3670003, 7340019, 14680051, 29360115, 58720243, 117440499, 234881011, 469762035, 939524083, 1879048179, 3758096371 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Prime numbers in this sequence are (43, 211, 883, 3571, 14323, 57331, 234881011, 3758096371, 3848290697203, ... ) LINKS Vincenzo Librandi, Table of n, a(n) for n = 1..1000 Index entries for linear recurrences with constant coefficients, signature (3,-2). FORMULA a(n) = 3*a(n-1) - 2*a(n-2). - Vincenzo Librandi_, Jul 15 2012 G.f.: x*(1+12*x)/(1 - 3*x + 2*x^2). - Vincenzo Librandi, Jul 15 2012 EXAMPLE a(2) = 2*1  + 13 = 15; a(3) = 2*15 + 13 = 43; a(4) = 2*43 + 13 = 99. MATHEMATICA RecurrenceTable[{a[1]==1, a[n]==2*a[n-1]+13}, a, {n, 40}] (* Vincenzo Librandi, Jul 15 2012 *) LinearRecurrence[{3, -2}, {1, 15}, 30] (* Harvey P. Dale, Aug 26 2019 *) PROG (MAGMA) I:=[1]; [n le 1 select I[n] else 2*Self(n-1)+13: n in [1..30]]; // Vincenzo Librandi, Jul 15 2012 CROSSREFS Sequence in context: A072119 A069127 A137183 * A124708 A204734 A126369 Adjacent sequences:  A173870 A173871 A173872 * A173874 A173875 A173876 KEYWORD nonn,easy AUTHOR Vincenzo Librandi, Mar 06 2010 STATUS approved

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Last modified April 14 01:49 EDT 2021. Contains 342941 sequences. (Running on oeis4.)