Search: id:A077234 Results 1-1 of 1 results found. %I A077234 %S A077234 2,9,34,127,474,1769,6602,24639,91954,343177,1280754,4779839,17838602, %T A077234 66574569,248459674,927264127,3460596834,12915123209,48199896002, %U A077234 179884460799,671337947194,2505467327977,9350531364714,34896658130879 %N A077234 Bisection (odd part) of Chebyshev sequence with Diophantine property. %C A077234 -3*a(n)^2 + b(n)^2 = 13, with the companion sequence b(n)= A077235(n). %C A077234 The even part is A054491(n) with Diophantine companion A077236(n). %H A077234 Index entries for sequences related to linear recurrences with constant coefficients %H A077234 Tanya Khovanova, Recursive Sequences %H A077234 Index entries for sequences related to Chebyshev polynomials. %F A077234 a(n)= 2*S(n, 4)+S(n-1, 4), with S(n, x) := U(n, x/2), Chebyshev polynomials of 2nd kind, A049310. S(-1, x) := 0 and S(n, 4)= A001353(n+1). %F A077234 G.f.: (2+x)/(1-4*x+x^2). %F A077234 a(n)=4*a(n-1)-a(n-2) with a(0)=2 and a(1)=9. [From Philippe DELEHAM (kolotoko(AT)wanadoo.fr), Nov 16 2008] %F A077234 a(n)=-(5/6)*sqrt(3)*[2-sqrt(3)]^n+(5/6)*sqrt(3)*[2+sqrt(3)]^n+[2-sqrt(3)]^n+[2+sqrt(3)]^n, with n>=0 [From Paolo P. Lava (ppl(AT)spl.at), Nov 20 2008] %e A077234 3*a(1)^2 + 13 = 3*81+13 = 256 = 16^2 = A077235(1)^2. %Y A077234 Cf. A077237 (even and odd parts). %Y A077234 Sequence in context: A000524 A120989 A010763 this_sequence A091526 A150937 A150938 %Y A077234 Adjacent sequences: A077231 A077232 A077233 this_sequence A077235 A077236 A077237 %K A077234 nonn,easy %O A077234 0,1 %A A077234 Wolfdieter Lang (wolfdieter.lang(AT)physik.uni-karlsruhe.de), Nov 08 2002 Search completed in 0.001 seconds