A116917 a(1)=a(2)=1. a(n) = A006530(a(n-1)) + A006530(a(n-2)).

1, 1, 2, 3, 5, 8, 7, 9, 10, 8, 7, 9, 10, 8, 7, 9, 10, 8, 7, 9, 10, 8, 7, 9, 10, 8, 7, 9, 10, 8, 7, 9, 10, 8, 7, 9, 10, 8, 7, 9, 10, 8, 7, 9, 10, 8, 7, 9, 10, 8, 7, 9, 10, 8, 7, 9, 10, 8, 7, 9, 10, 8, 7, 9, 10, 8, 7, 9, 10, 8, 7, 9, 10, 8, 7, 9, 10, 8, 7, 9, 10, 8, 7, 9, 10, 8, 7, 9, 10, 8, 7, 9, 10, 8

Offset: 1

Author

Leroy Quet, Feb 26 2006

Keywords

• easy
• nonn

Links

• Index entries for linear recurrences with constant coefficients, signature (1, -1, 1).

Crossrefs

Cf. A006530.

Programs

Mathematica

PadRight[{1,1,2,3,5},100,{10,8,7,9}] (* Harvey P. Dale, Jun 09 2013 *)

Formula

For n >= 1, a(4n+2) = 8, a(4n+3) = 7, a(4n+4) = 9, a(4n+5) = 10.

From Chai Wah Wu, Sep 06 2019: (Start)

a(n) = a(n-1) - a(n-2) + a(n-3) for n > 8.

G.f.: x*(-5*x^7 - x^6 - 4*x^5 - 3*x^4 - x^3 - 2*x^2 - 1)/((x - 1)*(x^2 + 1)). (End)

a(n) = (17+cos(n*Pi/2)+3*sin(n*Pi/2))/2 for n>=6. - Wesley Ivan Hurt, May 07 2021