The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A316246 Decimal expansion of the least x such that 1/x + 1/(x+1) + 1/(x+2) = 3. 4
 1, 7, 9, 2, 5, 1, 7, 2, 1, 3, 9, 7, 4, 3, 4, 0, 2, 9, 1, 7, 3, 0, 1, 7, 3, 3, 1, 4, 9, 4, 1, 4, 1, 5, 5, 8, 5, 7, 5, 9, 8, 7, 3, 8, 2, 6, 2, 9, 1, 3, 2, 2, 0, 1, 9, 9, 0, 1, 2, 7, 7, 0, 6, 3, 9, 2, 5, 8, 4, 5, 3, 7, 8, 4, 1, 6, 1, 0, 5, 3, 4, 8, 6, 3, 2, 1 (list; constant; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Equivalently, the least root of 3*x^3 + 6*x^2 - 2; Middle root: A316247; Greatest root: A316248. See A305328 for a guide to related sequences. LINKS FORMULA greatest root: -2/3 + (4/3)*cos((1/3)*arctan(3*sqrt(7))) **** middle: -2/3 - (2/3)*cos((1/3)*arctan(3*sqrt(7))) + 2*sin((1/3)*arctan(3*sqrt(7)))/sqrt(3) **** least: -2/3 - (2/3)*cos((1/3)*arctan(3*sqrt(7))) - 2*sin((1/3)*arctan(3*sqrt(7)))/sqrt(3) EXAMPLE greatest root: 0.5148689384387165869... middle root: -0.7223517244643762951... least root: -1.792517213974340291... MATHEMATICA a = 1; b = 1; c = 1; u = 0; v = 1; w = 2; d = 3; r[x_] := a/(x + u) + b/(x + v) + c/(x + w); t = x /. ComplexExpand[Solve[r[x] == d, x]] N[t, 20] u = N[t, 200]; RealDigits[u[[1]]]  (* A316246, greatest *) RealDigits[u[[2]]]  (* A316247, least *) RealDigits[u[[3]]]  (* A316248, middle *) CROSSREFS Cf. A305328, A316247, A316248. Sequence in context: A154197 A094148 A154215 * A249546 A110793 A199290 Adjacent sequences:  A316243 A316244 A316245 * A316247 A316248 A316249 KEYWORD nonn,cons AUTHOR Clark Kimberling, Aug 19 2018 EXTENSIONS a(86) corrected by Andrew Howroyd, Nov 04 2018 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified February 27 18:19 EST 2020. Contains 332307 sequences. (Running on oeis4.)