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 A134945 #46 Feb 10 2025 12:01:30
%S A134945 3,2,3,6,0,6,7,9,7,7,4,9,9,7,8,9,6,9,6,4,0,9,1,7,3,6,6,8,7,3,1,2,7,6,
%T A134945 2,3,5,4,4,0,6,1,8,3,5,9,6,1,1,5,2,5,7,2,4,2,7,0,8,9,7,2,4,5,4,1,0,5,
%U A134945 2,0,9,2,5,6,3,7,8,0,4,8,9,9,4,1,4,4,1,4
%N A134945 Decimal expansion of 1 + sqrt(5).
%C A134945 If "index" equals (0,2) then this sequence is the decimal expansion of (golden ratio divided by 5 = phi/5 = (1 + sqrt(5))/10). Example: 0.323606797...
%C A134945 Apart from the leading digit the same as A134972, A098317 and A002163. - _R. J. Mathar_, Aug 06 2013
%C A134945 Length of the longest diagonal in a regular 10-gon with unit side. - _Mohammed Yaseen_, Nov 12 2020
%C A134945 Abscissa of the first superstable point of the logistic map (see Finch). - _Stefano Spezia_, Nov 23 2024
%D A134945 Steven R. Finch, Mathematical Constants, Encyclopedia of Mathematics and its Applications, vol. 94, Cambridge University Press, 2003, Section 1.9, p. 66.
%H A134945 <a href="/index/Al#algebraic_02">Index entries for algebraic numbers, degree 2</a>.
%F A134945 From _Christian Katzmann_, Mar 19 2018: (Start)
%F A134945 Equals Sum_{n>=0} (15*(2*n)!+8*n!^2)/(n!^2*3^(2*n+2)).
%F A134945 Equals 1 + Sum_{n>=0} 5*(2*n)!/(n!^2*3^(2*n+1)). (End)
%F A134945 Equals 1/A019827. - _R. J. Mathar_, Jan 17 2021
%F A134945 Equals Product_{k>=1} (1 + 1/Fibonacci(2*k)). - _Amiram Eldar_, May 27 2021
%e A134945 3.2360679774997896964...
%t A134945 RealDigits[1 + Sqrt[5], 10, 100][[1]] (* _Michael De Vlieger_, Nov 13 2020 *)
%o A134945 (PARI) 1 + sqrt(5) \\ _Altug Alkan_, Mar 19 2018
%Y A134945 Cf. A000045, A002163, A098317, A134972.
%K A134945 nonn,cons
%O A134945 1,1
%A A134945 _Omar E. Pol_, Nov 15 2007
%E A134945 More terms from _Jinyuan Wang_, Mar 30 2020