login
Decimal expansion of the value of Minkowski's question mark function at the base of the natural logarithm.
1

%I #4 Jul 10 2011 18:41:28

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

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

%U 9,7,5,9,0,0,0,5,5,6,5,7,1,1,6,2,1,4,9,2,2,4,3,2,7,1,7,5,9,5,0,6

%N Decimal expansion of the value of Minkowski's question mark function at the base of the natural logarithm.

%H <a href="/index/Me#MinkowskiQ">Index entries for sequences related to Minkowski's question mark function</a>

%F 2 + 2(Sum[(-1)^(k)/2^(1/9*k^2 + k - 1), {k, 3, n, 3}] + Sum[(-1)^(k)/2^((1/9)(k + 8)(k - 1)), {k, 4, n, 3}] + Sum[(-1)^(k)/2^((1/9)(k^2 + 5*k - 5)), {k, 2, n, 3}])

%e 2.8154182545813457028113360074114866042343093040646539506191797214836975900055657...

%t RealDigits[(cf = ContinuedFraction[E, 150(*arbitrary precision*)]; IntegerPart[E] + Sum[(-1)^(k)/2^(Sum[cf[[i]], {i, 2, k}] - 1), {k,2, Length[cf]}]), 10, 100]

%Y Cf. A120025.

%K cons,nonn

%O 1,1

%A Joseph Biberstine (jrbibers(AT)indiana.edu), Jun 04 2006