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 A171663 Expansion of (1 + 4*x - 6*x^2 - 16*x^3 + 20*x^4)/((1-x)*(1-2*x)*(1+2*x)*(1-2*x^2)). 1
 1, 5, 5, 13, 25, 41, 113, 145, 481, 545, 1985, 2113, 8065, 8321, 32513, 33025, 130561, 131585, 523265, 525313, 2095105, 2099201, 8384513, 8392705, 33546241, 33562625, 134201345, 134234113, 536838145, 536903681, 2147418113, 2147549185 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 LINKS G. C. Greubel, Table of n, a(n) for n = 0..1000 Yu Tsumura, Primality tests for Fermat numbers and 2^(2k+1) +/- 2^(k+1)+1, arXiv:0912.2116 [math.NT], Dec 10 2009. Index entries for linear recurrences with constant coefficients, signature (1,6,-6,-8,8). FORMULA G.f.: (1 + 4*x - 6*x^2 - 16*x^3 + 20*x^4)/((1-x)*(1-2*x)*(1+2*x)*(1-2*x^2)). - Colin Barker, Apr 27 2013 MATHEMATICA Flatten[Table[2^(2*n+1) + 1 + 2^(n+1) {-1, 1}, {n, 0, 40}]] (* J. Mulder (jasper.mulder(AT)planet.nl), Jan 28 2010 *) PROG (PARI) my(x='x+O('x^40)); Vec((1+4*x-6*x^2-16*x^3+20*x^4)/((1-x)*(1- 2*x^2)*(1-4*x^2))) \\ G. C. Greubel, Jun 01 2019 (Magma) R:=PowerSeriesRing(Integers(), 40); Coefficients(R!( (1+4*x-6*x^2-16*x^3+20*x^4)/((1-x)*(1- 2*x^2)*(1-4*x^2)) )); // G. C. Greubel, Jun 01 2019 (Sage) ((1+4*x-6*x^2-16*x^3+20*x^4)/((1-x)*(1- 2*x^2)*(1-4*x^2))).series(x, 40).coefficients(x, sparse=False) # G. C. Greubel, Jun 01 2019 CROSSREFS Cf. A000040, A000215, A019434. Cf. A092440, A085601 (bisections). - R. J. Mathar, Jan 25 2010 Sequence in context: A094904 A286456 A352209 * A126439 A318541 A076903 Adjacent sequences: A171660 A171661 A171662 * A171664 A171665 A171666 KEYWORD easy,nonn AUTHOR Jonathan Vos Post, Dec 14 2009 EXTENSIONS More terms from R. J. Mathar and J. Mulder (jasper.mulder(AT)planet.nl), Jan 25 2010 New name from Joerg Arndt, Jun 03 2019 STATUS approved

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Last modified December 7 11:41 EST 2023. Contains 367656 sequences. (Running on oeis4.)