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 A162773 a(n) = ((2+sqrt(5))*(5+sqrt(5))^n + (2-sqrt(5))*(5-sqrt(5))^n)/2. 4
 2, 15, 110, 800, 5800, 42000, 304000, 2200000, 15920000, 115200000, 833600000, 6032000000, 43648000000, 315840000000, 2285440000000, 16537600000000, 119667200000000, 865920000000000, 6265856000000000, 45340160000000000 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,1 COMMENTS Binomial transform of A162772. Fifth binomial transform of A162963. LINKS Harvey P. Dale, Table of n, a(n) for n = 0..1000 Index entries for linear recurrences with constant coefficients, signature (10, -20). FORMULA a(n) = 10*a(n-1) - 20*a(n-2) for n > 1; a(0) = 2, a(1) = 15. G.f.: (2-5*x)/(1-10*x+20*x^2). MATHEMATICA LinearRecurrence[{10, -20}, {2, 15}, 30] (* Harvey P. Dale, Dec 24 2012 *) PROG (MAGMA) Z:=PolynomialRing(Integers()); N:=NumberField(x^2-5); S:=[ ((2+r)*(5+r)^n+(2-r)*(5-r)^n)/2: n in [0..19] ]; [ Integers()!S[j]: j in [1..#S] ]; // Klaus Brockhaus, Jul 19 2009 CROSSREFS Cf. A162772, A162963. Sequence in context: A037635 A154635 A062808 * A140637 A022026 A026113 Adjacent sequences:  A162770 A162771 A162772 * A162774 A162775 A162776 KEYWORD nonn AUTHOR Al Hakanson (hawkuu(AT)gmail.com), Jul 13 2009 EXTENSIONS Edited and extended beyond a(5) by Klaus Brockhaus, Jul 19 2009 Formulae corrected and clarified by Harvey P. Dale, Dec 24 2012 STATUS approved

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Last modified September 30 21:27 EDT 2020. Contains 337440 sequences. (Running on oeis4.)