A145303 a(n) = ((8 + sqrt(8))^n + (8 - sqrt(8))^n)/2.
1, 8, 72, 704, 7232, 76288, 815616, 8777728, 94769152, 1024753664, 11088986112, 120037572608, 1299617939456, 14071782965248, 152369922834432, 1649898919297024, 17865667030024192, 193456332999753728
Offset: 0
Keywords
Links
- Index entries for linear recurrences with constant coefficients, signature (16, -56).
Programs
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Magma
Z
:= PolynomialRing(Integers()); N :=NumberField(x^2-8); S:=[ ((8+r8)^n+(8-r8)^n)/2: n in [0..17] ]; [ Integers()!S[j]: j in [1..#S] ]; // Klaus Brockhaus, Oct 20 2008
Formula
From R. J. Mathar, Oct 10 2008: (Start)
a(n) = 16*a(n-1) - 56*a(n-2).
G.f.: (1-8x)/(1-16x+56x^2).
a(n) = Sum_{k=0..n} 8^k*A098158(n,k). - Philippe Deléham, Oct 14 2008
Extensions
More terms from R. J. Mathar, Oct 10 2008
Edited by Klaus Brockhaus, Jul 09 2009
Comments