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A377806
Decimal expansion of the circumradius of a snub dodecahedron with unit edge length.
6
2, 1, 5, 5, 8, 3, 7, 3, 7, 5, 1, 1, 5, 6, 3, 9, 7, 0, 1, 8, 3, 6, 6, 2, 9, 0, 7, 6, 6, 9, 3, 0, 5, 8, 2, 7, 7, 0, 1, 6, 8, 5, 1, 2, 1, 8, 7, 7, 4, 8, 1, 1, 8, 2, 2, 4, 1, 2, 2, 1, 5, 4, 3, 0, 1, 2, 0, 0, 6, 7, 0, 8, 0, 9, 4, 9, 4, 8, 4, 0, 0, 0, 5, 3, 4, 2, 9, 9, 2, 6
OFFSET
1,1
FORMULA
Equals sqrt(1 + 1/(1 - A377849))/2.
Equals the real root closest to 2 of 4096*x^12 - 27648*x^10 + 47104*x^8 - 35776*x^6 + 13872*x^4 -2696*x^2 + 209.
EXAMPLE
2.1558373751156397018366290766930582770168512187748...
MATHEMATICA
First[RealDigits[Sqrt[1 + 1/(1 - Root[#^3 + 2*#^2 - GoldenRatio^2 &, 1])]/2, 10, 100]] (* or *)
First[RealDigits[PolyhedronData["SnubDodecahedron", "Circumradius"], 10, 100]]
CROSSREFS
Cf. A377804 (surface area), A377805 (volume), A377807 (midradius).
Cf. A179296 (analogous for a regular dodecahedron).
Cf. A377849.
Sequence in context: A152290 A248699 A032006 * A167158 A074392 A284428
KEYWORD
nonn,cons,easy
AUTHOR
Paolo Xausa, Nov 10 2024
STATUS
approved