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A395397
Decimal expansion of the volume of the solid of revolution formed by rotating the loop part of a Folium of Descartes about its axis of symmetry.
1
9, 4, 2, 3, 2, 7, 1, 2, 0, 2, 2, 1, 9, 8, 0, 0, 5, 0, 9, 3, 7, 9, 4, 2, 4, 7, 0, 0, 0, 1, 3, 6, 4, 9, 1, 8, 6, 9, 9, 0, 7, 5, 7, 0, 1, 0, 3, 7, 3, 6, 7, 3, 6, 6, 4, 7, 7, 3, 1, 8, 8, 6, 9, 8, 4, 6, 0, 4, 0, 7, 8, 9, 4, 1, 5, 5, 1, 8, 3, 8, 2, 7, 6, 0, 4, 5, 6, 5, 2, 5, 5, 5, 6, 0, 9, 8, 5, 7, 2, 1, 7, 8, 7, 8, 5
OFFSET
0,1
COMMENTS
The Folium of Descartes is a plane curve that can be described by x^3 + y^3 = 3*a*x*y. Here we take a = 1.
Its axis of symmetry is the line y = x.
REFERENCES
N. P. Bali and Usha Paul, A Textbook of Engineering Mathematics: for B.E., B.Tech. Semester I, Laxmi Publications (P) Ltd, 8th ed., 2014, pp. 139-140.
LINKS
Doand A. Cole, The Mystery of the SOR.
Eric Weisstein's World of Mathematics, Folium of Descartes.
FORMULA
Equals (Pi/(6*sqrt(2))) * (8*log(2)-3).
EXAMPLE
0.942327120221980050937942470001364918699075701037367...
MATHEMATICA
RealDigits[(Pi/(6*Sqrt[2])) * (8*Log[2]-3), 10, 120][[1]]
PROG
(PARI) (Pi/(6*sqrt(2))) * (8*log(2)-3)
CROSSREFS
KEYWORD
nonn,cons
AUTHOR
Amiram Eldar, Apr 21 2026
STATUS
approved