The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A245617 Decimal expansion of 'chi', a constant appearing in the asymptotic variance of the number of comparisons required for updating a digital search tree, in case of the "approximate counting" algorithm. 0
 1, 2, 3, 7, 4, 1, 2, 5, 7, 5, 7, 3, 6, 1, 1, 0, 2, 2, 8, 7, 1, 9, 6, 1, 0, 6, 4, 6, 6, 7, 2, 8, 7, 4, 2, 9, 7, 7, 3, 2, 0, 4, 8, 1, 9, 6, 5, 4, 8, 4, 4, 3, 8, 4, 4, 1, 7, 1, 8, 2, 5, 6, 4, 0, 5, 3, 0, 4, 2, 8, 8, 5, 0, 9, 1, 3, 8, 8, 5, 5, 8, 6, 1, 9, 3, 5, 2, 4, 9, 7, 6, 2, 6, 8, 4, 5, 3, 3, 4, 0 (list; constant; graph; refs; listen; history; text; internal format)
 OFFSET -11,2 REFERENCES Steven R. Finch, Mathematical Constants, Cambridge University Press, 2003, Section 5.14 Digital Search Tree Constants, p. 359. LINKS Steven R. Finch, Errata and Addenda to Mathematical Constants, p. 44. Eric Weisstein's Mathworld, Erdős-Borwein Constant, Tree Searching FORMULA chi = (1/log(2))*sum_{n >= 1} (1/n)*csch(2*Pi^2*(n/log(2))) = A245675 - 1. variance ~ 1/12 + Pi^2/(6log(2)^2) - alpha - beta - chi + tau(n), where alpha is A065442, beta is A065443 and tau(n) an oscillatory negligible function. EXAMPLE 0.000000000001237412575736110228719610646672874297732... MAPLE evalf(1/log(2)*sum(1/n*csch(2*Pi^2*n/log(2)), n=1..infinity), 120) # Vaclav Kotesovec, Nov 05 2014 MATHEMATICA digits = 100; chi = (1/Log[2])*NSum[(1/n)*Csch[2*Pi^2*(n/Log[2])], {n, 1, Infinity}, WorkingPrecision -> digits+5]; RealDigits[chi, 10, digits] // First CROSSREFS Cf. A065442, A065443, A245675. Sequence in context: A086516 A281962 A245675 * A109205 A285294 A115630 Adjacent sequences:  A245614 A245615 A245616 * A245618 A245619 A245620 KEYWORD nonn,cons AUTHOR Jean-François Alcover, Nov 05 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 January 20 10:55 EST 2022. Contains 350472 sequences. (Running on oeis4.)