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A245651 Decimal expansion of eta/xi = A086318/A086317, a coefficient associated with the asymptotics of the number of weakly binary trees. 1
3, 1, 8, 7, 7, 6, 6, 2, 5, 9, 2, 5, 0, 2, 9, 6, 7, 5, 4, 8, 0, 0, 8, 1, 7, 6, 9, 7, 7, 8, 0, 1, 3, 1, 8, 1, 9, 7, 2, 1, 2, 4, 1, 8, 6, 7, 8, 7, 8, 7, 0, 1, 7, 0, 1, 9, 7, 5, 4, 9, 6, 8, 1, 7, 8, 9, 5, 7, 3, 2, 3, 4, 2, 6, 0, 2, 2, 9, 9, 0, 0, 6, 4, 0, 9, 1 (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

Vincenzo Librandi, Table of n, a(n) for n = 0..1000

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.

Eric Weisstein's MathWorld, Weakly binary tree

EXAMPLE

0.31877662592502967548008176977801318197212418678787017019754968178957323426...

MATHEMATICA

digits = 103; Clear[c, k]; c[0] = 2; c[n_] := c[n] = c[n-1]^2 + 2; k[n_] := k[n] = (Sqrt[c[n]^2^(-n)]*Sqrt[3 + Sum[1/Product[c[j], {j, 1, k}], {k, 1, n}]])/(c[n]^2^(-n)*(2*Sqrt[Pi])); k[5]; k[n = 10]; While[RealDigits[k[n], 10, digits] != RealDigits[k[n-5], 10, digits], n = n+5]; RealDigits[k[n], 10, digits] // First

CROSSREFS

Cf. A086317, A086318.

Sequence in context: A270861 A208656 A242440 * A007023 A176103 A308666

Adjacent sequences:  A245648 A245649 A245650 * A245652 A245653 A245654

KEYWORD

nonn,cons

AUTHOR

Jean-François Alcover, Jul 28 2014

STATUS

approved

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Last modified July 15 14:25 EDT 2019. Contains 325031 sequences. (Running on oeis4.)