Home/Chain Registry/Block #503,919

Block #503,919

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 4/21/2014, 10:55:19 AM · Difficulty 10.8076 · 6,335,250 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
821151934c49a73d85f8246c8c1a8f37e055946577a15e6f38dd3133eb7a96b5

Height

#503,919

Difficulty

10.807631

Transactions

6

Size

2.27 KB

Version

2

Bits

0acec0ec

Nonce

119,919,945

Timestamp

4/21/2014, 10:55:19 AM

Confirmations

6,335,250

Merkle Root

65e16be3eb96ef01072705d286e9d65df8da0f11d3e88563dcedde223849ee5d
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.

1.439 × 10⁹⁸(99-digit number)
14390043783277486367…13070311750208003840
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
1.439 × 10⁹⁸(99-digit number)
14390043783277486367…13070311750208003839
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
2.878 × 10⁹⁸(99-digit number)
28780087566554972735…26140623500416007679
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
5.756 × 10⁹⁸(99-digit number)
57560175133109945470…52281247000832015359
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
1.151 × 10⁹⁹(100-digit number)
11512035026621989094…04562494001664030719
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
2.302 × 10⁹⁹(100-digit number)
23024070053243978188…09124988003328061439
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
4.604 × 10⁹⁹(100-digit number)
46048140106487956376…18249976006656122879
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
9.209 × 10⁹⁹(100-digit number)
92096280212975912752…36499952013312245759
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
1.841 × 10¹⁰⁰(101-digit number)
18419256042595182550…72999904026624491519
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
3.683 × 10¹⁰⁰(101-digit number)
36838512085190365101…45999808053248983039
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
7.367 × 10¹⁰⁰(101-digit number)
73677024170380730202…91999616106497966079
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 503919

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 821151934c49a73d85f8246c8c1a8f37e055946577a15e6f38dd3133eb7a96b5

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 #503,919 on Chainz ↗
Circulating Supply:57,957,633 XPM·at block #6,839,168 · updates every 60s
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