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 A146963 a(n) = ((3 + sqrt(7))^n + (3 - sqrt(7))^n)/2. 4
 1, 3, 16, 90, 508, 2868, 16192, 91416, 516112, 2913840, 16450816, 92877216, 524361664, 2960415552, 16713769984, 94361788800, 532743192832, 3007735579392, 16980927090688, 95870091385344, 541258694130688 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 COMMENTS Binomial transform of A108851. Inverse binomial transform of A146964. LINKS Vincenzo Librandi, Table of n, a(n) for n = 0..158 FORMULA From Philippe Deléham and Klaus Brockhaus, Nov 05 2008: (Start) a(n) = 6*a(n-1) - 2*a(n-2); a(0)=1, a(1)=3. G.f.: (1-3*x)/(1-6*x+2*x^2). (End) a(n) = (Sum_{k=0..n} A098158(n,k)*3^(2*k)*7^(n-k))/3^n. - Philippe Deléham, Nov 06 2008 MATHEMATICA Transpose[NestList[Join[{Last[#], 6Last[#]-2First[#]}]&, {1, 3}, 25]] [[1]]  (* or *) CoefficientList[Series[(1-3x)/(1-6x+2x^2), {x, 0, 25}], x]  (* Harvey P. Dale, Apr 11 2011 *) PROG (MAGMA) Z:= PolynomialRing(Integers()); N:=NumberField(x^2-7); S:=[ ((3+r7)^n+(3-r7)^n)/2: n in [0..20] ]; [ Integers()!S[j]: j in [1..#S] ]; // Klaus Brockhaus, Nov 05 2008 CROSSREFS Cf. A108851, A146964, A098158. Sequence in context: A151329 A026111 A026330 * A074562 A130744 A009124 Adjacent sequences:  A146960 A146961 A146962 * A146964 A146965 A146966 KEYWORD nonn AUTHOR Al Hakanson (hawkuu(AT)gmail.com), Nov 03 2008 EXTENSIONS Extended beyond a(7) by Klaus Brockhaus, Nov 05 2008 Edited by Klaus Brockhaus, Jul 16 2009 STATUS approved

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Last modified May 21 01:18 EDT 2019. Contains 323429 sequences. (Running on oeis4.)