login

Reminder: The OEIS is hiring a new managing editor, and the application deadline is January 26.

Decimal expansion of 'nu', a coefficient related to the variance for searching corresponding to patricia tries.
3

%I #13 Dec 14 2024 09:17:24

%S 1,0,0,0,0,0,0,0,0,0,0,0,1,2,3,7,4,1,2,5,7,5,7,3,6,1,1,0,2,2,8,7,1,9,

%T 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,

%U 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

%N Decimal expansion of 'nu', a coefficient related to the variance for searching corresponding to patricia tries.

%C Curiously, this constant is very close to 1 (up to a 10^-12 gap). This can be explained via the Dedekind eta function, after Steven Finch.

%D Steven R. Finch, Mathematical Constants, Cambridge University Press, 2003, Section 5.11 Feller's coin tossing p. 341 and Section 5.14 Digital Search Tree Constants p. 356.

%H Vincenzo Librandi, <a href="/A245675/b245675.txt">Table of n, a(n) for n = 1..1000</a>

%H Wikipedia, <a href="http://en.wikipedia.org/wiki/Radix_tree">Radix tree</a>

%F nu = 1/12 + Pi^2/(6*log(2)^2) + 2*sigma/log(2), where sigma = sum_{k=1..infinity} (-1)^k/(k*(2^k-1)).

%e 1.000000000001237412575736110228719610646672874297732...

%t digits = 103; sigma = NSum[(-1)^k/(k*(2^k-1)), {k, 1, Infinity}, Method -> "AlternatingSigns", WorkingPrecision -> digits+10]; RealDigits[1/12 + Pi^2/(6*Log[2]^2) + 2*sigma/Log[2], 10, digits] // First

%Y Cf. A086311, A086312.

%K nonn,cons

%O 1,14

%A _Jean-François Alcover_, Jul 29 2014