chore: import upstream snapshot with attribution

clis/oeis/sequence.js

@@ -0,0 +1,71 @@
+// oeis sequence — full detail for a single OEIS sequence (A-number).
+//
+// OEIS' search endpoint, when given `q=id:Annnnnn`, returns one full record
+// with all sub-fields populated. We surface formula / xref / reference counts
+// instead of dumping the full graph.
+import { cli, Strategy } from '@jackwener/opencli/registry';
+import { EmptyResultError } from '@jackwener/opencli/errors';
+import { OEIS_BASE, formatId, oeisFetch, previewTerms, requireSequenceId } from './utils.js';
+
+function asArray(value) {
+    return Array.isArray(value) ? value : [];
+}
+
+cli({
+    site: 'oeis',
+    name: 'sequence',
+    access: 'read',
+    description: 'Full OEIS sequence detail by A-number (terms, name, keywords, formula counts)',
+    domain: 'oeis.org',
+    strategy: Strategy.PUBLIC,
+    browser: false,
+    args: [
+        { name: 'id', positional: true, required: true, help: 'OEIS sequence id (e.g. "A000045" for Fibonacci)' },
+    ],
+    columns: [
+        'id',
+        'name',
+        'keywords',
+        'preview',
+        'termCount',
+        'offset',
+        'author',
+        'created',
+        'revision',
+        'commentCount',
+        'formulaCount',
+        'referenceCount',
+        'xrefCount',
+        'linkCount',
+        'url',
+    ],
+    func: async (args) => {
+        const id = requireSequenceId(args.id);
+        const url = `${OEIS_BASE}/search?q=id:${encodeURIComponent(id)}&fmt=json`;
+        const body = await oeisFetch(url, 'oeis sequence');
+        const list = Array.isArray(body) ? body : [];
+        if (!list.length) {
+            throw new EmptyResultError('oeis sequence', `OEIS sequence "${id}" not found.`);
+        }
+        const r = list[0];
+        const data = typeof r?.data === 'string' ? r.data : '';
+        const termCount = data ? data.split(',').filter(Boolean).length : 0;
+        return [{
+            id: formatId(r?.number) ?? id,
+            name: typeof r?.name === 'string' ? r.name : null,
+            keywords: typeof r?.keyword === 'string' ? r.keyword : null,
+            preview: previewTerms(data),
+            termCount,
+            offset: typeof r?.offset === 'string' ? r.offset : null,
+            author: typeof r?.author === 'string' ? r.author : null,
+            created: typeof r?.created === 'string' ? r.created : null,
+            revision: typeof r?.revision === 'number' ? r.revision : null,
+            commentCount: asArray(r?.comment).length,
+            formulaCount: asArray(r?.formula).length,
+            referenceCount: asArray(r?.reference).length,
+            xrefCount: asArray(r?.xref).length,
+            linkCount: asArray(r?.link).length,
+            url: `${OEIS_BASE}/${formatId(r?.number) ?? id}`,
+        }];
+    },
+});