0,1

a(n)^2 - 3*b(n)^2 = 13, with the companion sequence b(n)= A077237(n).

Index entries for sequences related to Chebyshev polynomials.

a(2*k)= A077236(k) and a(2*k+1)= A077235(k), k>=0.

G.f.: (1-x)*(4+9*x+4*x^2)/(1-4*x^2+x^4).

11 = a(2) = sqrt(3*A077237(2)^2 + 13) = sqrt(3*6^2 + 13)= sqrt(121) = 11.

Sequence in context: A066898 A118143 A001350 this_sequence A000286 A036539 A000769

Adjacent sequences: A077235 A077236 A077237 this_sequence A077239 A077240 A077241

nonn,easy

Wolfdieter Lang (wolfdieter.lang(AT)physik.uni-karlsruhe.de), Nov 08 2002