Block #2,110,325

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 5/10/2017, 4:54:30 PM · Difficulty 10.9027 · 4,722,299 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
85dc19440b6aae969549de56f7fd8b473d48dc5996612618c0d780745fcf9a75

Height

#2,110,325

Difficulty

10.902680

Transactions

2

Size

5.47 KB

Version

2

Bits

0ae71602

Nonce

326,178,020

Timestamp

5/10/2017, 4:54:30 PM

Confirmations

4,722,299

Merkle Root

10e4bbb935c586f6a622dade53a1fa6186e38af04a8b68eeeee1ec47409465dd
Transactions (2)
1 in → 1 out8.4600 XPM109 B
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.

1.358 × 10⁹⁵(96-digit number)
13584239574538216144…31100380875218660801
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
1.358 × 10⁹⁵(96-digit number)
13584239574538216144…31100380875218660801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
2.716 × 10⁹⁵(96-digit number)
27168479149076432288…62200761750437321601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
5.433 × 10⁹⁵(96-digit number)
54336958298152864576…24401523500874643201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
1.086 × 10⁹⁶(97-digit number)
10867391659630572915…48803047001749286401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
2.173 × 10⁹⁶(97-digit number)
21734783319261145830…97606094003498572801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
4.346 × 10⁹⁶(97-digit number)
43469566638522291660…95212188006997145601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
8.693 × 10⁹⁶(97-digit number)
86939133277044583321…90424376013994291201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
1.738 × 10⁹⁷(98-digit number)
17387826655408916664…80848752027988582401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
3.477 × 10⁹⁷(98-digit number)
34775653310817833328…61697504055977164801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
6.955 × 10⁹⁷(98-digit number)
69551306621635666657…23395008111954329601
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:57,905,139 XPM·at block #6,832,623 · updates every 60s
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