Kolakoski Sequence

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exotic

What It Is

Kolakoski K = 1,2,2,1,1,2,1,2,2,1,2,2,1,1,2,... --- the unique infinite sequence over {1,2} starting with 1 whose run-length encoding equals itself. Density of 1s conjectured to be exactly 1/2 (Keane 1991, still open in 2026). Aperiodic, self-similar in run-length structure, complexity class unknown.

Interpretation

Standard analysis sees: bounded / light-tailed; few distinct values; anti-correlated (alternating); anti-persistent; blue spectrum (high-frequency power); homoskedastic; monofractal; stationary. The atlas finds no named structure, but the source is distinctively extreme on Nonstationarity:change_quantiles_mid (+5.5z) — beyond what the standard bank predicts for it.

What standard analysis sees
tail heaviness0.01
asymmetry0.44
occupancy0.06
short-range corr0.11
long-range memory0.10
spectral colour0.94
periodicity0.48
complexity0.39
time-irreversibility0.47
volatility clustering0.04
multifractality0.14
dimensionality0.53
nonstationarity0.03
What the atlas adds
Atlas-extreme metrics the standard bank can’t predict for this source
Nonstationarity:change_quantiles_mid+5.5zbank-miss 3.1σ
H3 Icosahedral:nn_enrichment+4.6zbank-miss 1.6σ
H3 Icosahedral:temporal_coherence+4.2zbank-miss 1.9σ
Projective ℙ²:collinearity-4.0zbank-miss 1.6σ
Spirograph:petal_symmetry+3.4zbank-miss 1.3σ
Lorentzian:crossing_density+2.9zbank-miss 2.0σ
Modular Residue:occupancy_entropy-2.4zbank-miss 1.0σ

Composition

dtypeint8
range[1, 2]
unique values2 / 16384
mean ± std1.5 ± 0.5

Binary sequence — two distinct symbols.

Render Gallery

Atlas Position

Nearest neighborDistance
Thue-Morse3.17
L-System (Dragon Curve)4.44
Symbolic Henon4.58

Open in Atlas →

Which Geometries Light Up

Catch24Catch24:DN_Spread_Stdrank 4/2980.5000
Catch24Catch24:SC_FluctAnal_2_rsrangefit_50_1_logi_prop_r1rank 295/2980.1220
H3 IcosahedralH3 Icosahedral:nn_enrichmentrank 3/2984.4933
H3 IcosahedralH3 Icosahedral:temporal_coherencerank 3/2980.3912
LaplacianLaplacian:cross_scale_curvature_coherencerank 294/298-0.5001
LorentzianLorentzian:crossing_densityrank 2/2980.6668
Mostow RigidityMostow Rigidity:distance_rigidityrank 2/2980.9844
NonstationarityNonstationarity:change_quantiles_midrank 3/2980.6666
Projective ℙ²Projective ℙ²:collinearityrank 296/2980.9324
Spherical S²Spherical S²:angular_spreadrank 3/2981.5708
Spherical S²Spherical S²:concentrationrank 296/2980.0015
SpirographSpirograph:petal_symmetryrank 5/2980.6658
Time ReversibilityTime Reversibility:increment_skewness_maxrank 294/2980.0007
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