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 A178255 #24 Aug 21 2023 12:17:50
%S A178255 3,5,6,1,5,5,2,8,1,2,8,0,8,8,3,0,2,7,4,9,1,0,7,0,4,9,2,7,9,8,7,0,3,8,
%T A178255 5,1,2,5,7,3,5,9,9,6,1,2,6,8,6,8,1,0,2,1,7,1,9,9,3,1,6,7,8,6,5,4,7,4,
%U A178255 7,7,1,7,3,1,6,8,8,1,0,7,9,6,7,9,3,9,3,1,8,2,5,4,0,5,3,4,2,1,4,8,3,4,2,2,7
%N A178255 Decimal expansion of (3+sqrt(17))/2.
%C A178255 Continued fraction expansion of (3+sqrt(17))/2 is A109007.
%C A178255 a(n) = A082486(n) for n > 1.
%C A178255 The rectangle R whose shape (i.e., length/width) is (3+sqrt(17))/2 can be partitioned into rectangles of shapes 3 and 3/2 in a manner that matches the periodic continued fraction [3, 3/2, 3, 3/2, ...]. R can also be partitioned into squares so as to match the periodic continued fraction [3, 1, 1, 3, 1, 1,...]. For details, see A188635. - _Clark Kimberling_, May 07 2011
%C A178255 The positive eigenvalue of the real symmetric 2 X 2 matrix M defined by M(i,j) = max(i,j) = [(1 2), (2 2)] is (3+sqrt(17))/2, while the negative one is (3-sqrt(17))/2. For a generalization, see A085984. - _Bernard Schott_, Apr 13 2020
%C A178255 A quadratic integer with minimal polynomial x^2 - 3x - 2. - _Charles R Greathouse IV_, Apr 14 2020
%C A178255 The positive root of x^2 - 3^x - 2. The negative root is -(-3 + sqrt(17))/2 = -0.56155... - _Wolfdieter Lang_, Dec 10 2022
%H A178255 <a href="/index/Al#algebraic_02">Index entries for algebraic numbers, degree 2</a>
%e A178255 (3+sqrt(17))/2 = 3.56155281280883027491...
%t A178255 FromContinuedFraction[{3, 3/2, {3, 3/2}}]
%t A178255 ContinuedFraction[%, 100] (* [3,1,1,3,1,1,...] *)
%t A178255 RealDigits[N[%%, 120]] (* A178255 *)
%t A178255 N[%%%, 40]
%t A178255 (* _Clark Kimberling_, May 07 2011 *)
%o A178255 (PARI) (3+sqrt(17))/2 \\ _Charles R Greathouse IV_, Apr 14 2020
%Y A178255 Cf. A082486 (decimal expansion of (5+sqrt(17))/2), A010473 (decimal expansion of sqrt(17)), A109007 (repeat 3, 1, 1), A085984.
%K A178255 cons,nonn
%O A178255 1,1
%A A178255 _Klaus Brockhaus_, May 24 2010