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 A073448 #19 May 15 2021 03:54:07
%S A073448 1,8,5,0,8,1,5,7,1,7,6,8,0,9,2,5,6,1,7,9,1,1,7,5,3,2,4,1,3,9,8,6,5,0,
%T A073448 1,9,3,4,7,0,3,9,6,6,5,5,0,9,4,0,0,9,2,9,8,8,3,5,1,5,8,2,7,7,8,5,8,8,
%U A073448 1,5,4,1,1,2,6,1,5,9,6,7,0,5,9,2,1,8,4,1,4,1,3,2,8,7,3,0,6,6,7,1,1,4,9,1,0
%N A073448 Decimal expansion of sec(1).
%C A073448 By the Lindemann-Weierstrass theorem, this constant is transcendental. - _Charles R Greathouse IV_, May 13 2019
%H A073448 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 A073448 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 A073448 <a href="/index/Tra#transcendental">Index entries for transcendental numbers</a>
%F A073448 Equals Sum_{k>=0} (-1)^k * E(2*k) / (2*k)!, where E(k) is the k-th Euler number (A122045). - _Amiram Eldar_, May 15 2021
%e A073448 1.85081571768092561791175324139...
%t A073448 RealDigits[Sec[1],10,120][[1]] (* _Harvey P. Dale_, Mar 13 2013 *)
%o A073448 (PARI) 1/cos(1)
%Y A073448 Cf. A049470 (cos(1)=1/A073448), A049469 (sin(1)), A049471 (tan(1)), A073447 (csc(1)), A073449 (cot(1)), A122045.
%K A073448 cons,nonn
%O A073448 1,2
%A A073448 _Rick L. Shepherd_, Aug 01 2002