Patterns /Sequences
Alternating Odd and Even Digits
Odd, even, odd, even — or the reverse — all the way through, as in 385274 or 1614. The digits themselves are free; only their parity is constrained.
Each digit after the first has its parity fixed but still has five values to choose from, so this pattern halves the possibilities at every position rather than pinning them outright. That gives it a middling count, visible above.
It is a genuinely different kind of structure from ABAB or repdigits: alternating parity is invisible until you look at the digits' oddness, which makes it one of the patterns players most often miss in the daily Pattern Hunt.
Because parity alternation constrains a property of digits rather than the digits themselves, it coexists happily with almost every other trait on the site.
Highest-scoring examples
The best-scoring numbers of four digits or more that carry this pattern. Shorter numbers are excluded here because their length alone dominates any score ranking.
Smallest examples
The first numbers in the range that match this pattern.
Related sequences patterns
Ascending Sequence Numbers
Every digit is exactly one higher than the one before it: 123, 4567, 456789. There are only a few dozen such numbers in the entire range.
Descending Sequence Numbers
Each digit is exactly one lower than the previous: 321, 6543, 987654. The mirror image of an ascending sequence, and just as scarce.
Ascending Digit Runs
A partial climb: somewhere in the number sit three or more digits each one higher than the last, as in the 456 inside 74560.
Descending Digit Runs
Three or more digits each one lower than the last, appearing anywhere in the number — the 543 inside 15432, for instance.
ABAB Pattern Numbers
Two digits taking strict turns: 5252, 8080, 393939. The pattern repeats with period two from the first digit to the last.