combinatorics.openverbs.com
LiveOtherThe n-th Catalan number Cₙ = C(2n, n)/(n+1), counting balanced bracketings, binary trees, and many other structures. Requires n ≤ 10000. (the service's own listing text)
9/9Recent Test Calls That Worked
525 msTypical Response Time (slow end: 742 ms)
$0.004 / $0.004Listed / Actual Price: match
Same AddressPayment Address (payTo): the same on all 8 checks of the main route
2Directories Listing It
2 h agoLast Checked (2026-10-24T03:40:16Z)
Listed Vs. Actual Price
Listed = the price in the directory listing today, for the main route we test. Actual = the price that route asked for when we called it (from our signed records). Some differences are normal, like prices that depend on the request.
| Period | Listed | Actual | Result |
|---|---|---|---|
| Recent Checks | $0.004 | $0.004 | Matches Listing |
Latest Signed Records
| Signed Record | Time (UTC) | Reply | Asked For Payment Correctly | ms | Price Asked |
|---|---|---|---|---|---|
| b56a1887aa67f885737e | 2026-10-24T03:40:16Z | 402 | Yes | 336 | $0.004 |
| b42e2a480b1d9e5c0d38 | 2026-10-24T01:50:16Z | 402 | Yes | 566 | $0.004 |
| 6a092d2f0f7f42b7294e | 2026-10-24T00:00:21Z | 402 | Yes | 631 | $0.004 |
| 085a0262027b59545fb5 | 2026-10-23T22:42:17Z | 402 | Yes | 319 | $0.004 |
| 58f17241f6d133e7cfb3 | 2026-10-23T20:56:16Z | 402 | Yes | 525 | $0.004 |
Every record is digitally signed, so anyone can verify it. More: raw data page · free quick check (JSON)