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 A147960 a(n) = ((9 + sqrt(2))^n + (9 - sqrt(2))^n)/2. 4
 1, 9, 83, 783, 7537, 73809, 733139, 7365591, 74662657, 762046137, 7818480563, 80531005311, 831898131121, 8612216940609, 89299952572403, 927034007995143, 9631915890692737, 100138799400852969, 1041577033850627219 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 COMMENTS Binomial transform of A147959. 9th binomial transform of A077957. - Philippe Deléham, Nov 30 2008 Hankel transform is := [1, 2, 0, 0, 0, 0, 0, 0, 0, 0, ...]. - Philippe Deléham, Dec 04 2008 LINKS G. C. Greubel, Table of n, a(n) for n = 0..980 Index entries for linear recurrences with constant coefficients, signature (18, -79). FORMULA From Philippe Deléham, Nov 19 2008: (Start) a(n) = 18*a(n-1) - 79*a(n-2), n > 1; a(0)=1, a(1)=9. G.f.: (1 - 9*x)/(1 - 18*x + 79*x^2). a(n) = (Sum_{k=0..n} A098158(n,k)*9^(2k)*2^(n-k))/9^n. (End) E.g.f.: exp(9*x)*cosh(sqrt(2)*x). - Ilya Gutkovskiy, Aug 11 2017 MATHEMATICA LinearRecurrence[{18, -79}, {1, 9}, 50] (* G. C. Greubel, Aug 17 2018 *) PROG (Magma) Z:= PolynomialRing(Integers()); N:=NumberField(x^2-2); S:=[ ((9+r2)^n+(9-r2)^n)/2: n in [0..19] ]; [ Integers()!S[j]: j in [1..#S] ]; // Klaus Brockhaus, Nov 19 2008 (PARI) x='x+O('x^30); Vec((1-9*x)/(1-18*x+79*x^2)) \\ G. C. Greubel, Aug 17 2018 CROSSREFS Cf. A077957, A098158, A147959. Sequence in context: A037679 A015579 A162759 * A155499 A321294 A242596 Adjacent sequences: A147957 A147958 A147959 * A147961 A147962 A147963 KEYWORD nonn AUTHOR Al Hakanson (hawkuu(AT)gmail.com), Nov 17 2008 EXTENSIONS Extended beyond a(6) by Klaus Brockhaus, Nov 19 2008 STATUS approved

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Last modified December 9 19:36 EST 2022. Contains 358703 sequences. (Running on oeis4.)