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 A146965 a(n) = 10*a(n-1) - 18*a(n-2); a(0)=1, a(1)=5. 2
 1, 5, 32, 230, 1724, 13100, 99968, 763880, 5839376, 44643920, 341330432, 2609713760, 19953189824, 152557050560, 1166413088768, 8918103977600, 68185604178176, 521330170184960, 3985960826642432, 30475665203095040 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 COMMENTS The Mathematica program implements the formula provided by Deleham and Brockhaus. - Harvey P. Dale, Feb 17 2011 LINKS Vincenzo Librandi, Table of n, a(n) for n = 0..145 Index entries for linear recurrences with constant coefficients, signature (10, -18). FORMULA a(n) = ((5 + sqrt(7))^n + (5 - sqrt(7))^n)/2. G.f.: (1-5*x)/(1-10*x+18*x^2). - Philippe Deléham and Klaus Brockhaus, Nov 05 2008 a(n) = (Sum_{k=0..n} A098158(n,k)*5^(2*k)*7^(n-k))/5^n. - Philippe Deléham, Nov 06 2008 MATHEMATICA Transpose[NestList[{#[[2]], 10#[[2]]-18#[[1]]}&, {1, 5}, 20]][[1]]  (* Harvey P. Dale, Feb 17 2011 *) LinearRecurrence[{10, -18}, {1, 5}, 30] (* Harvey P. Dale, Aug 27 2013 *) PROG (MAGMA) Z:= PolynomialRing(Integers()); N:=NumberField(x^2-7); S:=[ ((5+r7)^n+(5-r7)^n)/2: n in [0..19] ]; [ Integers()!S[j]: j in [1..#S] ]; // Klaus Brockhaus, Nov 05 2008 CROSSREFS Sequence in context: A208632 A065071 A153396 * A243693 A053157 A102231 Adjacent sequences:  A146962 A146963 A146964 * A146966 A146967 A146968 KEYWORD nonn AUTHOR Al Hakanson (hawkuu(AT)gmail.com), Nov 03 2008 EXTENSIONS Extended beyond a(7) by Klaus Brockhaus, Nov 05 2008 Name from Philippe Deléham and Klaus Brockhaus, Nov 05 2008 STATUS approved

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Last modified May 21 19:00 EDT 2019. Contains 323444 sequences. (Running on oeis4.)