Block #342,592

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 1/4/2014, 4:31:32 AM · Difficulty 10.1573 · 6,467,646 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
eb4847deb9036c0b4b60dd66c222972a67688e87a04140826a1d88fb1dd52edf

Height

#342,592

Difficulty

10.157323

Transactions

16

Size

6.74 KB

Version

2

Bits

0a28464b

Nonce

148,789

Timestamp

1/4/2014, 4:31:32 AM

Confirmations

6,467,646

Merkle Root

26c62f9e23ac7b8a80cd2561240ff9dcbec0e256176948217870c12a6155b084
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.

5.028 × 10¹⁰⁰(101-digit number)
50286343067869789251…79580348561971384321
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
5.028 × 10¹⁰⁰(101-digit number)
50286343067869789251…79580348561971384321
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
1.005 × 10¹⁰¹(102-digit number)
10057268613573957850…59160697123942768641
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
2.011 × 10¹⁰¹(102-digit number)
20114537227147915700…18321394247885537281
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
4.022 × 10¹⁰¹(102-digit number)
40229074454295831401…36642788495771074561
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
8.045 × 10¹⁰¹(102-digit number)
80458148908591662802…73285576991542149121
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
1.609 × 10¹⁰²(103-digit number)
16091629781718332560…46571153983084298241
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
3.218 × 10¹⁰²(103-digit number)
32183259563436665121…93142307966168596481
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
6.436 × 10¹⁰²(103-digit number)
64366519126873330242…86284615932337192961
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
1.287 × 10¹⁰³(104-digit number)
12873303825374666048…72569231864674385921
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
2.574 × 10¹⁰³(104-digit number)
25746607650749332096…45138463729348771841
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:57,725,981 XPM·at block #6,810,237 · updates every 60s
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