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 A322927 Expansion of x*(1 + 5*x + 40*x^2)/((1 - x^2)*(1 - 10*x^2)). 1
 0, 1, 5, 51, 55, 551, 555, 5551, 5555, 55551, 55555, 555551, 555555, 5555551, 5555555, 55555551, 55555555, 555555551, 555555555, 5555555551, 5555555555, 55555555551, 55555555555, 555555555551, 555555555555, 5555555555551, 5555555555555, 55555555555551 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,3 LINKS Muniru A Asiru, Table of n, a(n) for n = 0..1000 Index entries for linear recurrences with constant coefficients, signature (0,11,0,-10). FORMULA G.f.: x*(1 + 5*x + 40*x^2)/((1 - x^2)*(1 - 10*x^2)). a(n) = 11*a(n-2) - 10*a(n-4). a(n) = 5*(10^n - 1)/9 for n even; a(n) = (5*10^n - 41)/9 otherwise. MAPLE seq(coeff(series(x*(1+5*x+40*x^2)/((1-x^2)*(1-10*x^2)), x, n+1), x, n), n = 0 .. 30); # Muniru A Asiru, Mar 17 2019 MATHEMATICA CoefficientList[Series[x (1 + 5 x + 40 x^2) / (10 x^4 - 11 x^2 + 1), {x, 0, 25}], x] PROG (Magma) I:=[0, 1, 5, 51]; [n le 4 select I[n] else 11*Self(n-2)-10*Self(n-4): n in [1..30]]; CROSSREFS Bisections give: A002279 (even part), A173804 (odd part). Sequence in context: A160779 A077681 A326738 * A333261 A117710 A064019 Adjacent sequences: A322924 A322925 A322926 * A322928 A322929 A322930 KEYWORD nonn,easy AUTHOR Vincenzo Librandi, Mar 17 2019 STATUS approved

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Last modified March 26 04:20 EDT 2023. Contains 361529 sequences. (Running on oeis4.)