Home/Chain Registry/Block #517,063

Block #517,063

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 4/29/2014, 5:28:27 PM · Difficulty 10.8501 · 6,297,051 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
0d33bebc535d02abd0ecf5968fc4454bcde793c7dab74b44871af313a5d8edb3

Height

#517,063

Difficulty

10.850089

Transactions

5

Size

1.08 KB

Version

2

Bits

0ad99f73

Nonce

88,265,553

Timestamp

4/29/2014, 5:28:27 PM

Confirmations

6,297,051

Merkle Root

ae87359d16b4e18669370306508f46c68bc1b3771e2b065c6d29d531eb7775ca
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.

1.706 × 10⁹⁰(91-digit number)
17067230478531753064…23021804122672380320
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
1.706 × 10⁹⁰(91-digit number)
17067230478531753064…23021804122672380321
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
3.413 × 10⁹⁰(91-digit number)
34134460957063506128…46043608245344760641
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
6.826 × 10⁹⁰(91-digit number)
68268921914127012257…92087216490689521281
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
1.365 × 10⁹¹(92-digit number)
13653784382825402451…84174432981379042561
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
2.730 × 10⁹¹(92-digit number)
27307568765650804903…68348865962758085121
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
5.461 × 10⁹¹(92-digit number)
54615137531301609806…36697731925516170241
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
1.092 × 10⁹²(93-digit number)
10923027506260321961…73395463851032340481
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
2.184 × 10⁹²(93-digit number)
21846055012520643922…46790927702064680961
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
4.369 × 10⁹²(93-digit number)
43692110025041287844…93581855404129361921
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
8.738 × 10⁹²(93-digit number)
87384220050082575689…87163710808258723841
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 517063

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 0d33bebc535d02abd0ecf5968fc4454bcde793c7dab74b44871af313a5d8edb3

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 #517,063 on Chainz ↗
Circulating Supply:57,756,994 XPM·at block #6,814,113 · updates every 60s
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