This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A206612 #20 Mar 17 2025 15:45:34
%S A206612 13,6,19,25,44,69,113,182,295,477,772,1249,2021,3270,5291,8561,13852,
%T A206612 22413,36265,58678,94943,153621,248564,402185,650749,1052934,1703683,
%U A206612 2756617,4460300,7216917,11677217,18894134,30571351,49465485,80036836,129502321
%N A206612 Fibonacci sequence beginning 13, 6.
%H A206612 Vincenzo Librandi, <a href="/A206612/b206612.txt">Table of n, a(n) for n = 1..1000</a>
%H A206612 <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (1, 1).
%F A206612 From _Andrew Howroyd_, Aug 28 2018: (Start)
%F A206612 a(n) = a(n-1) + a(n-2) for n > 2.
%F A206612 a(n) = 13*Fibonacci(n) - 7*Fibonacci(n-1).
%F A206612 G.f.: x*(13 - 7*x)/(1 - x - x^2).
%F A206612 (End)
%t A206612 LinearRecurrence[{1, 1}, {13, 6}, 80]
%o A206612 (Magma) I:=[13, 6]; [n le 2 select I[n] else Self(n-1)+Self(n-2): n in [1..40]]; // _Vincenzo Librandi_, Feb 17 2012
%o A206612 (PARI) Vec((13 - 7*x)/(1 - x - x^2) + O(x^30)) \\ _Andrew Howroyd_, Aug 28 2018
%Y A206612 Cf. A000032, A000045, A206610, A206611.
%K A206612 nonn,easy
%O A206612 1,1
%A A206612 _Vladimir Joseph Stephan Orlovsky_, Feb 10 2012