A162356 a(n) = 8*a(n-1)-14*a(n-2) for n>1; a(0) = 2; a(1) = 9.
2, 9, 44, 226, 1192, 6372, 34288, 185096, 1000736, 5414544, 29306048, 158644768, 858873472, 4649961024, 25175459584, 136304222336, 737977344512, 3995559643392, 21632794323968, 117124519584256, 634137036138496
Offset: 0
Links
- Index entries for linear recurrences with constant coefficients, signature (8,-14).
Crossrefs
Programs
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Magma
Z
:=PolynomialRing(Integers()); N :=NumberField(x^2-2); S:=[ ((4+r)^(n+1)+(4-r)^(n+1))/4: n in [0..20] ]; [ Integers()!S[j]: j in [1..#S] ];
Formula
G.f.: (2-7*x)/(1-8*x+14*x^2).
a(n) = ((4+sqrt(2))^(n+1)+(4-sqrt(2))^(n+1))/4.
Comments