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!)
 A240943 Decimal expansion of the radius of convergence of Wedderburn-Etherington numbers g.f. 2
 4, 0, 2, 6, 9, 7, 5, 0, 3, 6, 7, 1, 4, 4, 1, 2, 9, 0, 9, 6, 9, 0, 4, 5, 3, 4, 8, 6, 5, 1, 0, 8, 3, 8, 0, 3, 4, 1, 7, 5, 5, 6, 7, 2, 1, 6, 2, 4, 9, 7, 2, 6, 5, 9, 2, 9, 1, 0, 5, 3, 4, 6, 4, 6, 0, 7, 6, 4, 2, 7, 2, 8, 9, 6, 6, 5, 2, 4, 2, 5, 8, 4, 1, 6, 4, 1, 6, 0, 9, 6, 0, 2, 6, 2, 1, 7, 2, 0, 5, 9, 5, 2 (list; constant; graph; refs; listen; history; text; internal format)
 OFFSET 0,1 REFERENCES Steven R. Finch, Mathematical Constants, Cambridge University Press, 2003, Section 5.6 Otter's Tree Enumeration Constants, p. 297. LINKS Nils Berglund, Yvain Bruned, BPHZ renormalisation and vanishing subcriticality limit of the fractional Phi_d^3 model, arXiv:1907.13028 [math.PR], 2019. Nils Berglund, Christian Kuehn, Model Spaces of Regularity Structures for Space-Fractional SPDEs, Journal of Statistical Physics, Springer Verlag, 2017, 168 (2), pp.331-368; HAL Id : hal-01432157. Nicolas Broutin and Philippe Flajolet, The height of random binary unlabelled trees, arXiv:0807.2365 [math.CO], 2008. Eric Weisstein's World of Mathematics, Weakly binary tree FORMULA 1/A086317. EXAMPLE 0.4026975036714412909690453486510838034175567216249726592910534646... MATHEMATICA digits = 102; n0 = 50; dn = 50; Clear[rho]; rho[n_] := rho[n] = (Clear[c]; c[0] = 0; y[z_] = Sum[c[k]*z^k, {k, 0, n}]; eq[0] = Rest[ Thread[CoefficientList[(-2*z + 2*y[z] - y[z]^2 - y[z^2])/2, z] == 0]]; s[1] = First[Solve[First[eq[0]], c[1]]]; Do[eq[k-1] = Rest[eq[k-2]] /. s[k-1]; s[k] = First[Solve[First[eq[k-1]], c[k]]], {k, 2, n}]; z /. FindRoot[ 2*z + y[z^2] == 1 /. Flatten[Table[s[k], {k, 1, n}]], {z, 1/2}, WorkingPrecision -> digits+10]); rho[n0]; rho[n = n0 + dn]; While[RealDigits[rho[n], 10, digits] != RealDigits[rho[n - dn], 10, digits], Print["n = ", n]; n = n + dn]; RealDigits[rho[n], 10, digits] // First (* or, after A086317: *) Clear[c, xi]; c[0] = 2; c[n_] := c[n] = c[n-1]^2 + 2; xi[n_Integer] := xi[n] = c[n]^(2^-n); xi[5]; xi[n = 10]; While[RealDigits[xi[n], 10, digits] != RealDigits[xi[n-5], 10, digits], n = n+5]; RealDigits[1/xi[n], 10, digits] // First (* Jean-François Alcover, Aug 04 2014 *) CROSSREFS Cf. A001190, A086317. Sequence in context: A016679 A178903 A322259 * A271823 A011352 A275983 Adjacent sequences:  A240940 A240941 A240942 * A240944 A240945 A240946 KEYWORD nonn,cons AUTHOR Jean-François Alcover, Aug 04 2014 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 May 16 04:53 EDT 2021. Contains 343937 sequences. (Running on oeis4.)