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 A084183 Jacobsthal reverse-pair sequence. 5
 0, 1, 1, 5, 3, 21, 11, 85, 43, 341, 171, 1365, 683, 5461, 2731, 21845, 10923, 87381, 43691, 349525, 174763, 1398101, 699051, 5592405, 2796203, 22369621, 11184811, 89478485, 44739243, 357913941, 178956971, 1431655765, 715827883, 5726623061 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,4 COMMENTS Reverses elements a(2n+1) and a(2n+2) in A001045. LINKS Vincenzo Librandi, Table of n, a(n) for n = 0..1000 Index entries for linear recurrences with constant coefficients, signature (-1,4,4). FORMULA G.f.: x*(1 + 2*x + 2*x^2)/((1+x)(1+2x)(1-2x)). a(n) = (5*2^n - 6*0^n + 4(-1)^n - 3(-2)^n)/12. - Paul Barry, May 19 2003 a(n) - 2*a(n-1) is a signed version of A000225. - Paul Curtz, Mar 06 2008 MATHEMATICA LinearRecurrence[{-1, 4, 4}, {0, 1, 1, 5}, 40] (* Harvey P. Dale, Nov 26 2022 *) PROG (Magma) [(5*2^n-6*0^n+4*(-1)^n-3*(-2)^n)/12: n in [0..40]]; // Vincenzo Librandi, Aug 13 2011 (PARI) a(n)=if(n, (5*2^n+4*(-1)^n-3*(-2)^n)/12, 0) \\ Charles R Greathouse IV, Oct 24 2014 CROSSREFS Sequence in context: A061037 A070262 A171621 * A099730 A072800 A199637 Adjacent sequences: A084180 A084181 A084182 * A084184 A084185 A084186 KEYWORD easy,nonn AUTHOR Paul Barry, May 19 2003 STATUS approved

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Last modified September 27 20:41 EDT 2023. Contains 365714 sequences. (Running on oeis4.)