REPEAT / RESIDUES / EXACT COUNTS
Watch the pattern repeat.
Check its shortest rhythm.
A valid repeat length can be larger than the shortest one. Enumerate a full justified period, test its divisors, and separate that pattern from a finite range.
Valid repeat—
Verified least period—
Underlying period density—
Decisions along the address line
Each cell shows stride · stripe · sieve · in range, in that order. ● passes, · fails. Green is the final selection; click for the exact residue.