Block #106,052

2CCLength 9★☆☆☆☆

Cunningham Chain of the Second Kind · Discovered 8/8/2013, 8:14:05 PM · Difficulty 9.5980 · 6,686,531 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
b8568a3f414da33e7be85a3c3ea9a30b1bec3ab83f2f660573276ed5098a76a0

Height

#106,052

Difficulty

9.598008

Transactions

2

Size

426 B

Version

2

Bits

09991707

Nonce

3,872

Timestamp

8/8/2013, 8:14:05 PM

Confirmations

6,686,531

Merkle Root

8f2a03575997178d722e4b91f90251b3b9fbd3f376e2a2d90a5745d2efa062bf
Transactions (2)
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.

9.604 × 10⁹⁶(97-digit number)
96042327116347772055…98485789870836433301
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
9.604 × 10⁹⁶(97-digit number)
96042327116347772055…98485789870836433301
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
1.920 × 10⁹⁷(98-digit number)
19208465423269554411…96971579741672866601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
3.841 × 10⁹⁷(98-digit number)
38416930846539108822…93943159483345733201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
7.683 × 10⁹⁷(98-digit number)
76833861693078217644…87886318966691466401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
1.536 × 10⁹⁸(99-digit number)
15366772338615643528…75772637933382932801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
3.073 × 10⁹⁸(99-digit number)
30733544677231287057…51545275866765865601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
6.146 × 10⁹⁸(99-digit number)
61467089354462574115…03090551733531731201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
1.229 × 10⁹⁹(100-digit number)
12293417870892514823…06181103467063462401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
2.458 × 10⁹⁹(100-digit number)
24586835741785029646…12362206934126924801
Verify on FactorDB ↗Wolfram Alpha ↗

What this block proved

The miner who found this block proved the existence of 9 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
CommonChain length 9

Found in most blocks. The baseline for Primecoin's proof-of-work.

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:57,584,633 XPM·at block #6,792,582 · updates every 60s
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