Home/Chain Registry/Block #531,536

Block #531,536

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 5/8/2014, 1:45:55 PM · Difficulty 10.8944 · 6,294,758 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
0832103d22a01bd316740bf0607f4e6928a8c10531b0e4063372a4b7d0050761

Height

#531,536

Difficulty

10.894396

Transactions

7

Size

2.04 KB

Version

2

Bits

0ae4f71b

Nonce

162,619

Timestamp

5/8/2014, 1:45:55 PM

Confirmations

6,294,758

Merkle Root

f9b126d7d2edbfc7e9e9f1365d34439707d9f81f57f179c44f3621c8b82a9d8d
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.

6.313 × 10⁹⁴(95-digit number)
63137706064928937233…37682652890380052150
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
6.313 × 10⁹⁴(95-digit number)
63137706064928937233…37682652890380052151
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
1.262 × 10⁹⁵(96-digit number)
12627541212985787446…75365305780760104301
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
2.525 × 10⁹⁵(96-digit number)
25255082425971574893…50730611561520208601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
5.051 × 10⁹⁵(96-digit number)
50510164851943149787…01461223123040417201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
1.010 × 10⁹⁶(97-digit number)
10102032970388629957…02922446246080834401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
2.020 × 10⁹⁶(97-digit number)
20204065940777259914…05844892492161668801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
4.040 × 10⁹⁶(97-digit number)
40408131881554519829…11689784984323337601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
8.081 × 10⁹⁶(97-digit number)
80816263763109039659…23379569968646675201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
1.616 × 10⁹⁷(98-digit number)
16163252752621807931…46759139937293350401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
3.232 × 10⁹⁷(98-digit number)
32326505505243615863…93518279874586700801
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 Second 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 2CC formula:

2CC: 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 531536

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 0832103d22a01bd316740bf0607f4e6928a8c10531b0e4063372a4b7d0050761

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 #531,536 on Chainz ↗
Circulating Supply:57,854,490 XPM·at block #6,826,293 · updates every 60s
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