0,5

A036799 gives the positions of zeros in this sequence.

Between two zeros, the graph of the sequence looks like a Takagi (or blancmange) curve.

Rémy Sigrist, Table of n, a(n) for n = 0..10000

Wikipedia, Blancmange curve

a(n) = Sum_{i=0..n-1} (-1)^A076478(i) for any n>=0.

Cf. A076478, A036799.

Sequence in context: A154556 A260228 A316657 * A126626 A137927 A321864

Adjacent sequences: A277911 A277912 A277913 * A277915 A277916 A277917

nonn,base

Rémy Sigrist, Nov 03 2016

approved