Mian-Chowla

number-theory · 37 views
number-theoryarithmetic

What It Is

Greedy Sidon (B₂) sequence: a₁=1, a_{n+1} = smallest integer strictly greater than a_n such that all pairwise sums {a_i + a_j : i ≤ j} remain distinct. First terms 1, 2, 4, 8, 13, 21, 31, 45, 66, 81, ... (Mian–Chowla 1944; OEIS A005282). Emitted as a length-N binary indicator (255 at positions a_n < N, 0 elsewhere) shifted by an rng-chosen offset (additive translation, NOT cyclic --- a cyclic shift would break the Sidon property on ℤ/N). Density ~0.5% at N=16384. Canonical positive control for sumset-isolation metrics (Erdős #152 family): by construction every pairwise sum is uniquely realized.

Interpretation

Standard analysis sees: heavy-tailed; right-skewed; few distinct values; low-complexity (predictable, not noise-like); multifractal; nonstationary / drifting. The atlas finds no named structure, but the source is distinctively extreme on G2 Root System:pair_angle_kurtosis (+3.6z) — beyond what the standard bank predicts for it.

What standard analysis sees
tail heaviness0.98
asymmetry0.98
occupancy0.00
short-range corr0.37
long-range memory0.62
spectral colour0.65
periodicity0.19
complexity0.01
time-irreversibility0.51
volatility clustering0.33
multifractality0.88
nonstationarity0.95
What the atlas adds
Atlas-extreme metrics the standard bank can’t predict for this source
G2 Root System:pair_angle_kurtosis+3.6zbank-miss 1.7σ
Boltzmann:coupling_temporal_variance+3.1zbank-miss 2.6σ
Mostow Rigidity:margulis_ratio+2.9zbank-miss 1.2σ
Cayley:spectral_gap+2.8zbank-miss 2.9σ
Ulam Spiral (Square):polynomial_concentration-2.8zbank-miss 1.9σ
Boltzmann:spectral_gap_J-2.7zbank-miss 1.9σ
Nonstationarity:ac1_trend+2.4zbank-miss 2.0σ
Laplacian:poisson_recovery_error-2.4zbank-miss 2.1σ

Composition

dtypeuint8
range[0, 255]
unique values2 / 16384
mean ± std1.14 ± 17

Binary sequence — two distinct symbols.

Render Gallery

Atlas Position

Nearest neighborDistance
Rainfall (ORD Hourly)4.26cross-origin
Neural Net (Pruned 90%)4.59cross-origin
Devil's Staircase5.04cross-origin

Open in Atlas →

Which Geometries Light Up

2-adic › 2-adic:valuation_transition_predictabilityrank 4/3060.9836
2-adic › 2-adic:multiscale_markov_predictabilityrank 5/3060.9885
2-adic › 2-adic:distance_entropyrank 306/3060.0613
2-adic › 2-adic:mean_distancerank 306/3060.0075
Boltzmann › Boltzmann:coupling_temporal_variancerank 1/3062.0000
Catch24 › Catch24:SB_TransitionMatrix_3ac_sumdiagcovrank 2/3060.3240
Catch24 › Catch24:CO_HistogramAMI_even_2_5rank 302/3060.0000
Catch24 › Catch24:DN_OutlierInclude_p_001_mdrmdrank 302/306-0.4766
Catch24 › Catch24:DN_Meanrank 303/3060.0047
Catch24 › Catch24:SB_MotifThree_quantile_hhrank 305/3060.0600
Cayley › Cayley:growth_exponentrank 5/3061.9972
Cayley › Cayley:spectral_gaprank 5/3060.0299
Cayley › Cayley:delta_hyp_normrank 305/3060.0000
Chladni › Chladni:nodal_gap_ratiorank 305/3060.0337
D4 Triality › D4 Triality:triplet_temporalrank 4/3060.8000
D4 Triality › D4 Triality:edge_ortho_polarityrank 304/3060.0112
Fisher Information › Fisher Information:log_det_fisherrank 3/306141.2201
Fisher Information › Fisher Information:trace_fisherrank 3/306229810.4834
G2 Root System › G2 Root System:pair_angle_kurtosisrank 3/306102.1322
G2 Root System › G2 Root System:short_long_ratiorank 3/3060.9953
Higher-Order Statistics › Higher-Order Statistics:skew_meanrank 5/3062.4716
Higher-Order Statistics › Higher-Order Statistics:perm_entropyrank 302/3060.0250
Hodge–Laplacian › Hodge–Laplacian:source_fractionrank 305/3060.0182
Inflation (Substitution) › Inflation (Substitution):discrepancyrank 305/3060.0000
Klein Bottle › Klein Bottle:rank_deficitrank 2/3060.9875
Klein Bottle › Klein Bottle:rank_deficit_maxrank 3/3060.9975
Klein Bottle › Klein Bottle:wht_spectral_kurtosisrank 306/3061.3812
Level Statistics › Level Statistics:spacing_gue_distancerank 1/3060.9953
Level Statistics › Level Statistics:spacing_poisson_distancerank 1/3060.9953
Mostow Rigidity › Mostow Rigidity:mean_turn_anglerank 3/3060.9868
Mostow Rigidity › Mostow Rigidity:laplacian_perturbation_stabilityrank 304/3060.6197
Möbius-S³ › Möbius-S³:phase_profile_deviationrank 1/3060.7858
Nonstationarity › Nonstationarity:ac1_trendrank 5/3060.1726
Nonstationarity › Nonstationarity:variance_trendrank 302/306-0.2063
Predictability › Predictability:sample_entropyrank 305/3060.0100
Projective ℙ² › Projective ℙ²:cross_ratio_stdrank 305/3060.0000
SL(2,ℝ) (Thurston) › SL(2,ℝ) (Thurston):cocycle_growth_raterank 3/3061.9815
Spirograph › Spirograph:rational_grid_proximityrank 306/3060.4352
Symplectic › Symplectic:recurrence_raterank 3/3060.9772
Time Reversibility › Time Reversibility:ordinal_reversal_distancerank 306/3060.0000
Ulam Spiral (Square) › Ulam Spiral (Square):polynomial_concentrationrank 305/3060.0078
Visibility Graph › Visibility Graph:degree_r_squaredrank 1/3060.9926
Visibility Graph › Visibility Graph:assortativityrank 304/306-0.4059
Wasserstein › Wasserstein:concentrationrank 1/30631.8488
Wasserstein › Wasserstein:dist_from_uniformrank 4/3060.4798
Wasserstein › Wasserstein:entropyrank 306/3060.0433
Zariski › Zariski:nonsep_fractionrank 1/3060.9821
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