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%I #33 May 15 2021 03:53:56
%S 1,5,5,7,4,0,7,7,2,4,6,5,4,9,0,2,2,3,0,5,0,6,9,7,4,8,0,7,4,5,8,3,6,0,
%T 1,7,3,0,8,7,2,5,0,7,7,2,3,8,1,5,2,0,0,3,8,3,8,3,9,4,6,6,0,5,6,9,8,8,
%U 6,1,3,9,7,1,5,1,7,2,7,2,8,9,5,5,5,0,9,9,9,6,5,2,0,2,2,4,2,9,8
%N Decimal expansion of tan(1).
%C By the Lindemann-Weierstrass theorem, this constant is transcendental. - _Charles R Greathouse IV_, May 13 2019
%H Harry J. Smith, <a href="/A049471/b049471.txt">Table of n, a(n) for n = 1..20000</a>
%H Mohammad K. Azarian, <a href="http://www.jstor.org/stable/30044897">Forty-Five Nested Equilateral Triangles and cosecant of 1 degree, Problem 813</a>, College Mathematics Journal, Vol. 36, No. 5, November 2005, pp. 413-414.
%H Mohammad K. Azarian, <a href="http://www.jstor.org/stable/27646393">Solution of Forty-Five Nested Equilateral Triangles and cosecant of 1 degree, Problem 813</a>, College Mathematics Journal, Vol. 37, No. 5, November 2006, pp. 394-395.
%H <a href="/index/Tra#transcendental">Index entries for transcendental numbers</a>
%F Equals Sum_{k>=1} (-1)^(k+1) * B(2*k) * 2^(2*k) * (2^(2*k) - 1) / (2*k)!, where B(k) is the k-th Bernoulli number. - _Amiram Eldar_, May 15 2021
%e 1.5574077246549022305...
%t RealDigits[Tan[1], 10, 100][[1]] (* _Amiram Eldar_, May 15 2021 *)
%o (PARI) default(realprecision, 20080); x=tan(1); for (n=1, 20000, d=floor(x); x=(x-d)*10; write("b049471.txt", n, " ", d)); \\
%Y Cf. A093178 (continued fraction), A009001, A073449.
%K cons,easy,nonn
%O 1,2
%A Albert du Toit (dutwa(AT)intekom.co.za), _N. J. A. Sloane_
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