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 A101604 a(n) = 2*a(n-1) + 5*a(n-2) + 2*a(n-3). 0
 1, 2, 9, 30, 109, 386, 1377, 4902, 17461, 62186, 221481, 788814, 2809405, 10005842, 35636337, 126920694, 452034757, 1609945658, 5733906489, 20421610782, 72732645325, 259041157538, 922588763265, 3285848604870, 11702723341141 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 COMMENTS Transform of 2^n under Riordan array A101603. LINKS Index entries for linear recurrences with constant coefficients, signature (2,5,2). FORMULA G.f.: 1/((1+x)*(1-3*x-2*x^2)); a(n) = (3/4 + sqrt(17)/4)^n*(1/4 + 7*sqrt(17)/68) + (1/4 - 7*sqrt(17)/68)*(3/4 - sqrt(17)/4)^n + (-1)^n/2; a(n) = (A007483(n) + (-1)^n)/2. - R. J. Mathar, Sep 21 2012 CROSSREFS Cf. A007483, A101603. Sequence in context: A201164 A289901 A261330 * A234007 A203365 A181954 Adjacent sequences:  A101601 A101602 A101603 * A101605 A101606 A101607 KEYWORD easy,nonn AUTHOR Paul Barry, Dec 08 2004 STATUS approved

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Last modified September 18 01:03 EDT 2021. Contains 347498 sequences. (Running on oeis4.)