0,3

This is the r=20 member of the r-family of sequences S_r(n), n>=1, defined in A092184 where more information can be found.

Index entries for sequences related to Chebyshev polynomials.

a(n) = 1/16*{-2+[9+4*sqrt(5)]^n+[9-4*sqrt(5)]^n}. - R. Stephan, Apr 14 2004

a(n)=(T(n, 9)-1)/8 with Chebyshev's polynomials of the first kind evaluated at x=9: T(n, 9)=A023039(n). W. Lang (wolfdieter.lang_AT_physik_DOT_uni-karlsruhe_DOT_de), Oct 18 2004

G.f.: x*(1+x)/((1-x)*(1-18*x+x^2)) = x*(1+x)/(1-19*x+19*x^2-x^3) (from the Stephan link, see A092184).

Sequence in context: A053508 A060918 A115100 this_sequence A014901 A000564 A019580

Adjacent sequences: A049680 A049681 A049682 this_sequence A049684 A049685 A049686

nonn

Clark Kimberling (ck6(AT)evansville.edu)