# Reported issues for oeis-mcp-server

Pod holds 6 of 6 GitHub reports that passed its relevance review. This can include external user reports, maintainer-confirmed bugs, and concrete feature gaps. Treat them as evidence to inspect, not a count of distinct defects.

Back to [oeis-mcp-server](/mcp/oeis-mcp-server).

## Most discussed

### feat(oeis_identify_sequence): state the 60-term limit and give terms a readable validation error

### Use case

`oeis_identify_sequence` rejects more than 60 terms, a term longer than 200 digits, a decimal, or a separator other than a comma or space. Neither the tool nor the `terms` description states those limits, and every such input fails with the same raw pattern:

```text
terms: Invalid string: must match pattern /^(-?\d{1,200}|_)(,(-?\d{1,200}|_)){0,59}$/
```

A caller that pastes a whole data line (often more than 60 terms; A305309 has 138) has to decode `{0,59}` to learn what went…

[Read the thread](https://github.com/cyanheads/oeis-mcp-server/issues/4) · 2026-10-01 · closed · 2 comments

### feat(oeis_get_terms): bound each slice by bytes as well as by limit

### Use case

`oeis_get_terms` caps a slice by count only (`limit`, up to 1000), but terms are arbitrary-precision strings, so the reply size depends on the values. On A000045 from n = 1000, the default `limit` of 100 already returns 48 KB, and `limit: 1000` returns 662 KB (about 165k tokens) in one call. A caller cannot know term sizes before asking.

Seen on 0.1.0, mcp-ts-core 0.13.10, Node 26.5.0, HTTP transport.

### Proposed behavior

Stop a slice at a byte budget as well as at `limit`…

[Read the thread](https://github.com/cyanheads/oeis-mcp-server/issues/3) · 2026-10-01 · closed · 2 comments

### bug(oeis_get_sequence): reserved (allocated) A-numbers fail as "unrecognized format", here and in any search page that lists one

### Server version

0.1.0

### mcp-ts-core version

0.13.10

### Runtime

Node.js

### Runtime version

Node 26.5.0

### Transport

HTTP (Streamable HTTP)

### Description

Reserved entries (keyword `allocated`) carry no offset: the JSON record has no `offset` field and the `fmt=text` search page has no `%O` line. `normalizeRecord` and the search parser both read that as a format change and throw a non-retryable `upstream_unparseable`. As a result `oeis_get_sequence` and…

[Read the thread](https://github.com/cyanheads/oeis-mcp-server/issues/2) · 2026-10-01 · closed · 2 comments

### bug(oeis_get_terms): synthesized b-files reported as source "bfile", and the result depends on cache state

### Server version

0.1.0

### mcp-ts-core version

0.13.10

### Runtime

Node.js

### Runtime version

Node 26.5.0

### Transport

HTTP (Streamable HTTP)

### Description

oeis.org answers `/A######/b######.txt` with `200` for entries that have no b-file, serving a file synthesized from the data line (first line `# A181630 (b-file synthesized from sequence entry)`). `oeis_get_terms` treats only a `404` as "no b-file", so on a cold cache it reports `source: "bfile"` and a `bFileUrl` for terms…

[Read the thread](https://github.com/cyanheads/oeis-mcp-server/issues/1) · 2026-10-01 · closed · 2 comments

### bug(oeis_search_sequences): space-separated terms with a negative are split into separate searches, with no notice

### Server version

0.1.1

### mcp-ts-core version

0.13.10

### Runtime

Node.js

### Runtime version

Node 26.5.0

### Transport

stdio

### Description

OEIS reads bare numbers as one `seq:` run when commas separate them, or spaces with no negative term. Spaces alone split the run at a negative term, and OEIS searches the pieces separately. `oeis_search_sequences` treats every numbers-only query as one run: a page with results gives no sign of the split, and a zero-hit gives run advice (drop…

[Read the thread](https://github.com/cyanheads/oeis-mcp-server/issues/13) · 2026-10-02 · open · 0 comments

### bug(oeis_get_terms): a b-file miss is cached for 7 days, so an entry that gains a b-file keeps returning its data line

### Server version

0.1.1

### mcp-ts-core version

0.13.10

### Runtime

Bun

### Runtime version

1.4.2

### Transport

stdio

### OS

Any

### Description

`OeisService.getBFile` caches a b-file `404` (or OEIS's synthesized no-b-file file) for the 7-day b-file TTL, while a record is revalidated after 24 h and a record `404` after 1 h. When an entry gains a b-file, `oeis_get_terms` keeps serving the data line and says the entry has no b-file, even after the record it reads in the same call…

[Read the thread](https://github.com/cyanheads/oeis-mcp-server/issues/12) · 2026-10-02 · open · 0 comments

## Most recent

The remaining reports are on [the project's issue tracker](https://github.com/cyanheads/oeis-mcp-server/issues).