0,2

-3*a(n)^2 + b(n)^2 = 13, with the companion sequence b(n)= A077238(n).

Index entries for sequences related to Chebyshev polynomials.

a(2*k)= A054491(k) and a(2*k+1)= A077234(k), k>=0.

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

3*a(2)^2 + 13 = 3*36+13 = 121 = 11^2 = A077238(2)^2.

Sequence in context: A047161 A048083 A127931 this_sequence A056879 A006746 A121624

Adjacent sequences: A077234 A077235 A077236 this_sequence A077238 A077239 A077240

nonn,easy

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