A sequence analogous to the Lucas numbers (A000032), with ratios converging to Pi.

A085422

A sequence analogous to the Lucas numbers (A000032), with ratios converging to Pi.

Terms

    a(0) =-1a(1) =2a(2) =4a(3) =13a(4) =40a(5) =125a(6) =392a(7) =1231a(8) =3867a(9) =12148a(10) =38164a(11) =119895a(12) =376661a(13) =1183315a(14) =3717493a(15) =11678848a(16) =36690183a(17) =115265609a(18) =362117590a(19) =1137625960a(20) =3573957358a(21) =11227918180a(22) =35273545269a(23) =110815110683a(24) =348135937628

External references