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A138500
Decimal expansion of arc length of the quadrifolium.
3
9, 6, 8, 8, 4, 4, 8, 2, 2, 0, 5, 4, 7, 6, 7, 6, 1, 9, 8, 4, 2, 8, 5, 0, 3, 1, 9, 6, 3, 9, 1, 8, 2, 9, 4, 1, 1, 9, 5, 3, 9, 1, 8, 3, 9, 7, 8, 8, 6, 6, 0, 0, 8, 2, 5, 0, 8, 3, 1, 1, 6, 3, 5, 2, 4, 6, 2, 1, 2, 0, 6, 4, 5, 9, 6, 2, 5, 5, 2, 1, 4, 8, 2, 9, 3, 4, 0, 0, 9, 4, 7, 4, 3, 3, 5, 8, 3, 9, 1, 8, 4, 9, 7, 9, 8
OFFSET
1,1
COMMENTS
Also the perimeter of an ellipse with semi-axis lengths 2 and 1. - Jeremy Tan, May 31 2016
LINKS
Eric Weisstein's World of Mathematics, Quadrifolium
EXAMPLE
9.6884482205476761984...
MAPLE
evalf(8*EllipticE(sqrt(3)/2), 120); # Vaclav Kotesovec, Apr 22 2015
MATHEMATICA
RealDigits[8 EllipticE[3/4], 10, 120][[1]] (* Harvey P. Dale, Jun 20 2011 *)
PROG
(SageMath) numerical_approx( 8*elliptic_ec(3/4), digits=130) # G. C. Greubel, Apr 22 2024
CROSSREFS
Sequence in context: A021512 A154205 A258407 * A161484 A103985 A153071
KEYWORD
nonn,cons
AUTHOR
Eric W. Weisstein, Mar 20 2008
STATUS
approved