cp's OEIS Frontend

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.

A093728 Decimal expansion of 2E(2i sqrt(2)), where E(k) is the complete elliptic integral of the 2nd kind.

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%I A093728 #23 Feb 16 2025 08:32:53
%S A093728 6,6,8,2,4,4,6,6,1,0,2,7,7,6,2,9,1,1,5,0,6,4,7,5,1,1,6,2,5,3,0,0,9,8,
%T A093728 1,1,9,7,0,0,4,9,1,3,3,6,1,9,4,5,8,8,5,5,1,6,4,6,4,8,0,1,9,8,2,4,6,2,
%U A093728 9,2,7,0,9,5,2,3,2,8,4,8,0,4,0,1,2,9,5,5,3,2,4,0,5,8,1,9,9,1,0,6,4,5
%N A093728 Decimal expansion of 2E(2i sqrt(2)), where E(k) is the complete elliptic integral of the 2nd kind.
%C A093728 Arc length of the trifolium r = a*cos(3*theta).
%H A093728 G. C. Greubel, <a href="/A093728/b093728.txt">Table of n, a(n) for n = 1..10000</a>
%H A093728 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/Trifolium.html">Trifolium</a>
%F A093728 Equals 2*A249491. - _Altug Alkan_, Oct 02 2018
%e A093728 6.68244661027762911506475116253009811970049133619458855164648...
%p A093728 Re(evalf(2*EllipticE(2*I*sqrt(2)), 120)); # _Vaclav Kotesovec_, Apr 22 2015
%t A093728 RealDigits[ N[ 2*EllipticE[-8], 102]][[1]] (* _Jean-François Alcover_, Oct 29 2012 *)
%o A093728 (PARI) 2*intnum(t=0,Pi/2,sqrt(1+8*sin(t)^2)) \\ _Charles R Greathouse IV_, Aug 15 2015
%Y A093728 Cf. A249491.
%K A093728 nonn,cons
%O A093728 1,1
%A A093728 _Eric W. Weisstein_, Apr 13 2004