Home/Chain Registry/Block #290,067

Block #290,067

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 12/2/2013, 12:29:37 PM · Difficulty 9.9889 · 6,502,719 confirmations

1CC
Cunningham Chain of the First Kind

A sequence where each prime is double the previous prime plus one.

Block Header
Block Hash
fe592987a93680c888e66390e25dac0d982d4498ec2ce46b693cbbcaca646d57

Height

#290,067

Difficulty

9.988946

Transactions

5

Size

2.57 KB

Version

2

Bits

09fd2b8c

Nonce

3,633

Timestamp

12/2/2013, 12:29:37 PM

Confirmations

6,502,719

Merkle Root

66cae9fae98904b8267f6bc6688517cf8513d98073e06643b02eed938dc1269f
Prime Chain Origin

This is the prime chain origin stored in the block header. It is a composite number (not prime itself) — it equals the first prime in the chain multiplied by a primorial. The origin anchors the entire chain to this specific block.

8.480 × 10¹⁰⁷(108-digit number)
84800711317154934687…71616748513189232000
Discovered Prime Numbers
p_k = 2^k × origin − 1

These are the actual prime numbers discovered by this block, computed using the verified Primecoin formula. Each number has been independently confirmed to pass the Fermat primality test. Use the FactorDB links to verify any number independently.

1
origin − 1
8.480 × 10¹⁰⁷(108-digit number)
84800711317154934687…71616748513189231999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
1.696 × 10¹⁰⁸(109-digit number)
16960142263430986937…43233497026378463999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
3.392 × 10¹⁰⁸(109-digit number)
33920284526861973874…86466994052756927999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
6.784 × 10¹⁰⁸(109-digit number)
67840569053723947749…72933988105513855999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
1.356 × 10¹⁰⁹(110-digit number)
13568113810744789549…45867976211027711999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
2.713 × 10¹⁰⁹(110-digit number)
27136227621489579099…91735952422055423999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
5.427 × 10¹⁰⁹(110-digit number)
54272455242979158199…83471904844110847999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
1.085 × 10¹¹⁰(111-digit number)
10854491048595831639…66943809688221695999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
2.170 × 10¹¹⁰(111-digit number)
21708982097191663279…33887619376443391999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
4.341 × 10¹¹⁰(111-digit number)
43417964194383326559…67775238752886783999
Verify on FactorDB ↗Wolfram Alpha ↗

What this block proved

The miner who found this block proved the existence of 10 consecutive prime numbers forming a Cunningham Chain of the First Kind. The prime chain origin — the large number shown above — anchors the chain and is divisible by a primorial (the product of small primes), cryptographically tying these prime numbers to this specific block.

View full Prime Chain Discovery page →
★★☆☆☆
Rarity
UncommonChain length 10
How Primecoin's Proof-of-Work Constructs These Primes

Primecoin stores a value called the prime chain origin in each block. The miner found a large integer such that when divided by a primorial (the product of small primes: 2 × 3 × 5 × 7 × …), the result is the first prime in the chain. The origin is deliberately divisible by this primorial — that divisibility is part of the proof.

Prime Chain Origin = First Prime × Primorial (2·3·5·7·11·…)
Source: Primecoin prime.cpp — CheckPrimeProofOfWork()

This is why the origin has many small prime factors — those factors are the primorial divisor. The chain then extends from the first prime using the 1CC formula:

1CC: p₁ (first prime), p₂ = 2p₁ + 1, p₃ = 2p₂ + 1, …
Verify on a Primecoin Node

Anyone running a Primecoin node can independently verify this block using the following RPC commands. Run these from the primecoin-cli command line or via the debug console in the Primecoin wallet.

1. Get block hash by height
getblockhash 290067

Returns the block hash for a given block height. Use this to confirm the hash shown above matches the chain.

2. Get full block data
getblock fe592987a93680c888e66390e25dac0d982d4498ec2ce46b693cbbcaca646d57

Returns the full block header including difficulty, prime chain origin, prime chain type, transaction IDs, and all other fields shown on this page.

How to run these commands: To verify this data independently, open a terminal on your own Primecoin node and run primecoin-cli <command>. Alternatively, open the Primecoin-Qt wallet, go to Help → Debug Window → Console, and type the command directly. The node must be fully synced to this block height for the commands to return results.

Cross-reference on Chainz Explorer

Chainz is an independent Primecoin block explorer. Compare this block's data to verify accuracy.

View Block #290,067 on Chainz ↗
Circulating Supply:57,586,271 XPM·at block #6,792,785 · updates every 60s
xpmprime.info is a work in progress. If you enjoy using this service you can support this project with a Primecoin donation.