A138498 Decimal expansion of arc length of Freeth's nephroid.

2, 1, 2, 0, 3, 4, 0, 5, 9, 0, 7, 4, 8, 4, 7, 2, 1, 0, 2, 0, 6, 6, 0, 9, 5, 8, 3, 7, 4, 4, 3, 0, 8, 2, 7, 1, 8, 8, 2, 2, 5, 5, 2, 2, 0, 1, 5, 5, 9, 5, 3, 9, 5, 9, 6, 3, 2, 5, 9, 2, 1, 8, 3, 0, 2, 7, 2, 4, 1, 9, 5, 2, 7, 8, 5, 0, 9, 2, 6, 8, 9, 7, 4, 7, 5, 4, 4, 5, 8, 1, 1, 6, 4, 7, 4, 1, 1, 9, 8, 3, 9, 5, 8, 6, 5

Offset

2,1

Links

Table of n, a(n) for n=2..106.

Eric Weisstein's World of Mathematics, Freeth's Nephroid

Example

21.203405907484721020...

Maple

evalf((8*(3*EllipticE(sqrt(2/3)) - 3*EllipticK(sqrt(2/3)) + 4*EllipticPi(-1/3, sqrt(2/3))))/sqrt(3), 120); # Vaclav Kotesovec, Apr 22 2015

Mathematica

(8*(3*EllipticE[2/3] - 3*EllipticK[2/3] + 4*EllipticPi[ -1/3, 2/3]))/Sqrt[3]

Crossrefs

Sequence in context: A344788 A372687 A068076 * A379016 A276669 A307596

Adjacent sequences: A138495 A138496 A138497 * A138499 A138500 A138501

Keyword

nonn,cons

Author

Eric W. Weisstein, Mar 20 2008

Status

approved