Block #316,113

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 12/16/2013, 9:20:07 PM · Difficulty 10.1266 · 6,490,559 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
42a2f59144a57c36e655e19b265ce520eddbdf896b651d0d4ed24874c7a7c280

Height

#316,113

Difficulty

10.126563

Transactions

13

Size

5.64 KB

Version

2

Bits

0a206675

Nonce

23,494

Timestamp

12/16/2013, 9:20:07 PM

Confirmations

6,490,559

Merkle Root

4afe1365a900a27a5a382fcb3441f067eb035851dba2b67f428a3d894dc14316
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.

4.629 × 10¹⁰³(104-digit number)
46292736139720309431…27545058982265276161
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
4.629 × 10¹⁰³(104-digit number)
46292736139720309431…27545058982265276161
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
9.258 × 10¹⁰³(104-digit number)
92585472279440618863…55090117964530552321
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
1.851 × 10¹⁰⁴(105-digit number)
18517094455888123772…10180235929061104641
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
3.703 × 10¹⁰⁴(105-digit number)
37034188911776247545…20360471858122209281
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
7.406 × 10¹⁰⁴(105-digit number)
74068377823552495090…40720943716244418561
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
1.481 × 10¹⁰⁵(106-digit number)
14813675564710499018…81441887432488837121
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
2.962 × 10¹⁰⁵(106-digit number)
29627351129420998036…62883774864977674241
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
5.925 × 10¹⁰⁵(106-digit number)
59254702258841996072…25767549729955348481
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
1.185 × 10¹⁰⁶(107-digit number)
11850940451768399214…51535099459910696961
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
2.370 × 10¹⁰⁶(107-digit number)
23701880903536798428…03070198919821393921
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.

★★☆☆☆
Rarity
UncommonChain length 10

Roughly 1 in 100 blocks. Solid but expected in a healthy network.

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, …
Circulating Supply:57,697,468 XPM·at block #6,806,671 · updates every 60s
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