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 A084568 a(0)=1, a(1)=5, a(n+2)=4a(n), n>0. 1
 1, 5, 8, 20, 32, 80, 128, 320, 512, 1280, 2048, 5120, 8192, 20480, 32768, 81920, 131072, 327680, 524288, 1310720, 2097152, 5242880, 8388608, 20971520, 33554432, 83886080, 134217728, 335544320, 536870912, 1342177280, 2147483648 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 COMMENTS Binomial transform is A080926 (without leading zero). LINKS Table of n, a(n) for n=0..30. Index entries for linear recurrences with constant coefficients, signature (0,4) FORMULA G.f.: (1+5*x+4*x^2)/((1+2*x)*(1-2*x)). E.g.f.: (9*exp(2*x)-exp(-2*x))/4-exp(0). a(n) = (9*2^n-(-2)^n)/4-0^n. MATHEMATICA Join[{1}, LinearRecurrence[{0, 4}, {5, 8}, 30]] (* Harvey P. Dale, Sep 12 2013 *) CROSSREFS Cf. A080926, A104721. Sequence in context: A271195 A270630 A272217 * A340509 A198635 A178675 Adjacent sequences: A084565 A084566 A084567 * A084569 A084570 A084571 KEYWORD nonn,easy AUTHOR Paul Barry, May 30 2003 STATUS approved

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Last modified September 19 19:23 EDT 2024. Contains 376014 sequences. (Running on oeis4.)