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 A146964 a(n) = ((4 + sqrt(7))^n + (4 - sqrt(7))^n))/2. 2
 1, 4, 23, 148, 977, 6484, 43079, 286276, 1902497, 12643492, 84025463, 558412276, 3711069041, 24662841844, 163903113383, 1089259330468, 7238946623297, 48108239012164, 319715392487639, 2124748988791636, 14120553377944337 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 COMMENTS Binomial transform of A146963. Inverse binomial transform of A146965. LINKS Vincenzo Librandi, Table of n, a(n) for n = 0..300 FORMULA From Philippe Deléham and Klaus Brockhaus, Nov 05 2008: (Start) a(n) = 8*a(n-1) - 9*a(n-2); a(0)=1, a(1)=4. G.f.: (1-4*x)/(1-8*x+9*x^2). (End) a(n) = (Sum_{k=0..n} A098158(n,k)*4^(2*k)*7^(n-k))/4^n. - Philippe Deléham, Nov 06 2008 PROG (MAGMA) Z:= PolynomialRing(Integers()); N:=NumberField(x^2-7); S:=[ ((4+r7)^n+(4-r7)^n)/2: n in [0..20] ]; [ Integers()!S[j]: j in [1..#S] ]; // Klaus Brockhaus, Nov 05 2008 CROSSREFS Cf. A146963, A146965, A098158. Sequence in context: A162561 A277921 A020079 * A194006 A116881 A107089 Adjacent sequences:  A146961 A146962 A146963 * A146965 A146966 A146967 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 22 18:53 EDT 2019. Contains 323481 sequences. (Running on oeis4.)