Home/Chain Registry/Block #316,619

Block #316,619

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 12/17/2013, 4:42:38 AM · Difficulty 10.1377 · 6,500,606 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
02bdd30c41be63a140af9b11ca6b376e4e0aabcbffe8d988d82dd06e9bb5cbe7

Height

#316,619

Difficulty

10.137707

Transactions

16

Size

4.33 KB

Version

2

Bits

0a2340c6

Nonce

10,137

Timestamp

12/17/2013, 4:42:38 AM

Confirmations

6,500,606

Merkle Root

e23ca0f84d18b1c9a2a5cb7ffe592e1da2d0185b971a8136ae6e48694389387d
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.

3.007 × 10⁹⁸(99-digit number)
30072045022331812457…33464701401442540160
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
3.007 × 10⁹⁸(99-digit number)
30072045022331812457…33464701401442540161
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
6.014 × 10⁹⁸(99-digit number)
60144090044663624914…66929402802885080321
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
1.202 × 10⁹⁹(100-digit number)
12028818008932724982…33858805605770160641
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
2.405 × 10⁹⁹(100-digit number)
24057636017865449965…67717611211540321281
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
4.811 × 10⁹⁹(100-digit number)
48115272035730899931…35435222423080642561
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
9.623 × 10⁹⁹(100-digit number)
96230544071461799862…70870444846161285121
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
1.924 × 10¹⁰⁰(101-digit number)
19246108814292359972…41740889692322570241
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
3.849 × 10¹⁰⁰(101-digit number)
38492217628584719944…83481779384645140481
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
7.698 × 10¹⁰⁰(101-digit number)
76984435257169439889…66963558769290280961
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
1.539 × 10¹⁰¹(102-digit number)
15396887051433887977…33927117538580561921
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 316619

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 02bdd30c41be63a140af9b11ca6b376e4e0aabcbffe8d988d82dd06e9bb5cbe7

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 #316,619 on Chainz ↗
Circulating Supply:57,781,840 XPM·at block #6,817,224 · updates every 60s
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