Home/Chain Registry/Block #504,847

Block #504,847

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 4/22/2014, 1:11:15 AM · Difficulty 10.8104 · 6,319,816 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
e3758dd7707bb0036787b3039d5541ec9c731980f81e5e1d46eb2ebdde2db9fb

Height

#504,847

Difficulty

10.810442

Transactions

8

Size

1.89 KB

Version

2

Bits

0acf791d

Nonce

448,458,219

Timestamp

4/22/2014, 1:11:15 AM

Confirmations

6,319,816

Merkle Root

4294e5c52d2f209cca557361ee31b6ede6a4cf77b0e021c13910a549505f55cf
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.

9.024 × 10⁹⁸(99-digit number)
90243348872360521048…98720307786458521600
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
9.024 × 10⁹⁸(99-digit number)
90243348872360521048…98720307786458521601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
1.804 × 10⁹⁹(100-digit number)
18048669774472104209…97440615572917043201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
3.609 × 10⁹⁹(100-digit number)
36097339548944208419…94881231145834086401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
7.219 × 10⁹⁹(100-digit number)
72194679097888416838…89762462291668172801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
1.443 × 10¹⁰⁰(101-digit number)
14438935819577683367…79524924583336345601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
2.887 × 10¹⁰⁰(101-digit number)
28877871639155366735…59049849166672691201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
5.775 × 10¹⁰⁰(101-digit number)
57755743278310733471…18099698333345382401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
1.155 × 10¹⁰¹(102-digit number)
11551148655662146694…36199396666690764801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
2.310 × 10¹⁰¹(102-digit number)
23102297311324293388…72398793333381529601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
4.620 × 10¹⁰¹(102-digit number)
46204594622648586776…44797586666763059201
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 504847

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 e3758dd7707bb0036787b3039d5541ec9c731980f81e5e1d46eb2ebdde2db9fb

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 #504,847 on Chainz ↗
Circulating Supply:57,841,367 XPM·at block #6,824,662 · updates every 60s
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