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 A074621 a(n) = 6^n + 9^n. 1
 2, 15, 117, 945, 7857, 66825, 578097, 5062905, 44726337, 397498185, 3547250577, 31743856665, 284606318817, 2554926522345, 22955156619057, 206361317079225, 1855841298759297, 16694108359111305, 150196195253667537 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,1 LINKS Index entries for linear recurrences with constant coefficients, signature (15,-54). FORMULA From Mohammad K. Azarian, Jan 11 2009: (Start) G.f.: 1/(1-6*x) + 1/(1-9*x). E.g.f.: e^(6*x) + e^(9*x). (End) a(n) = 15*a(n-1) - 54*a(n-2) with a(0)=2, a(1)=15. - Vincenzo Librandi, Jul 21 2010 MATHEMATICA Table[6^n + 9^n, {n, 0, 20}] CROSSREFS Cf. A000051, A034472, A052539, A034474, A062394, A034491, A062395, A062396, A007689, A063376, A063481, A074600..A074624. Sequence in context: A052861 A300910 A161937 * A185758 A052448 A168502 Adjacent sequences:  A074618 A074619 A074620 * A074622 A074623 A074624 KEYWORD easy,nonn AUTHOR Robert G. Wilson v, Aug 26 2002 STATUS approved

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Last modified May 27 02:54 EDT 2019. Contains 323597 sequences. (Running on oeis4.)