Block #2,182,034

2CCLength 11★★★☆☆

Cunningham Chain of the Second Kind · Discovered 6/28/2017, 1:10:33 AM · Difficulty 10.9373 · 4,645,297 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
3257a0fa7462f08d4b2639f4f6f597aa2f587f6ae62dfe5e12fb1d3d56fc440b

Height

#2,182,034

Difficulty

10.937261

Transactions

2

Size

5.52 KB

Version

2

Bits

0aeff05a

Nonce

313,668,568

Timestamp

6/28/2017, 1:10:33 AM

Confirmations

4,645,297

Merkle Root

36a70605dd36f473fb0114922ff9206b2cdd4b413a8d5d12642d4cd0617f30cc
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.

2.511 × 10⁹⁵(96-digit number)
25113674101746271590…95418154594906846721
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
2.511 × 10⁹⁵(96-digit number)
25113674101746271590…95418154594906846721
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
5.022 × 10⁹⁵(96-digit number)
50227348203492543181…90836309189813693441
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
1.004 × 10⁹⁶(97-digit number)
10045469640698508636…81672618379627386881
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
2.009 × 10⁹⁶(97-digit number)
20090939281397017272…63345236759254773761
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
4.018 × 10⁹⁶(97-digit number)
40181878562794034545…26690473518509547521
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
8.036 × 10⁹⁶(97-digit number)
80363757125588069090…53380947037019095041
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
1.607 × 10⁹⁷(98-digit number)
16072751425117613818…06761894074038190081
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
3.214 × 10⁹⁷(98-digit number)
32145502850235227636…13523788148076380161
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
6.429 × 10⁹⁷(98-digit number)
64291005700470455272…27047576296152760321
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
1.285 × 10⁹⁸(99-digit number)
12858201140094091054…54095152592305520641
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
11
2^10 × origin + 1
2.571 × 10⁹⁸(99-digit number)
25716402280188182109…08190305184611041281
Verify on FactorDB ↗Wolfram Alpha ↗

What this block proved

The miner who found this block proved the existence of 11 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
RareChain length 11

Approximately 1 in 1,000 blocks. Noteworthy discoveries.

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:57,862,762 XPM·at block #6,827,330 · updates every 60s
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