# Argument selection: T646

This table holds exactly one real constant,
S = lim(K -> infinity) sum(k=0..K) (-1)^k c_k,
where c_k = sum(j=0..k) (-1)^j binomial(k,j)/zeta(2j+2).
It uses the ordinary Riemann zeta function, starts the coefficient index at
zero, and retains the signs of the coefficients. There are no free parameters.

Cisło and Wolf, *On the Riesz and Báez-Duarte criteria for the Riemann
Hypothesis* (arXiv:0807.2971), §4, equation (49), explicitly single out this
sum. OEIS A345412 records its decimal expansion and the same coefficient
convention. The family proposal in numberdb-data#283 selects this named
summation value, separate from the coefficient and Riesz-function tables.
The source is mathematical provenance; the issue is workflow provenance only.

The coverage review therefore finds one entry complete for this quantity.
There is no truncation of an argument family, no exploratory reference sample,
and no tunable generating-function input. Partial sums, ordinary sums,
residuals, and other generating-function arguments are different quantities
and are not added to enlarge the singleton. The computational truncation at
400 terms is an accuracy choice, not an argument-selection bound; its tail is
included in the enclosure. The default enumeration yields exactly one empty
parameter mapping, and the table has no Parameters declaration.

The live T644 and T645 documents were read. Their notation c_k, R(x), ordinary
zeta normalization, exact integer summation indices, and compatible tags are
preserved. T646 links to these companions without altering them. No statistic,
quantile, percentile, or conventional critical value is involved.

Policy evidence: agents/runs/20261101T082247Z-build-skills/manifest.json.
Both archived local and live canonical skills were read and byte-compared.
Each has SHA-256 a2b28d9953264d7b0ca62663785c2952190c5be6d6d3597fd695d9a54d606278.
This build justification is not the independent argument-selection acceptance.
The controller must obtain a separate critique and its fingerprinted sidecar.