Block #214,055

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 10/17/2013, 6:03:14 AM · Difficulty 9.9228 · 6,576,943 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
a526299531ac038560fc64a596853061bf000251a575df47b73010217f35f01e

Height

#214,055

Difficulty

9.922794

Transactions

4

Size

4.62 KB

Version

2

Bits

09ec3c3d

Nonce

91,388

Timestamp

10/17/2013, 6:03:14 AM

Confirmations

6,576,943

Merkle Root

b9b999efef00c78f2502fe8a41c38c3bf8d89c82ef09c42b55949d31a082aac7
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.

6.778 × 10⁹¹(92-digit number)
67789488895694897514…53308292864521711169
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
6.778 × 10⁹¹(92-digit number)
67789488895694897514…53308292864521711169
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
1.355 × 10⁹²(93-digit number)
13557897779138979502…06616585729043422339
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
2.711 × 10⁹²(93-digit number)
27115795558277959005…13233171458086844679
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
5.423 × 10⁹²(93-digit number)
54231591116555918011…26466342916173689359
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
1.084 × 10⁹³(94-digit number)
10846318223311183602…52932685832347378719
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
2.169 × 10⁹³(94-digit number)
21692636446622367204…05865371664694757439
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
4.338 × 10⁹³(94-digit number)
43385272893244734409…11730743329389514879
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
8.677 × 10⁹³(94-digit number)
86770545786489468818…23461486658779029759
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
1.735 × 10⁹⁴(95-digit number)
17354109157297893763…46922973317558059519
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
3.470 × 10⁹⁴(95-digit number)
34708218314595787527…93845946635116119039
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 First 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 1CC formula:

1CC: p₁ (first prime), p₂ = 2p₁ + 1, p₃ = 2p₂ + 1, …
Circulating Supply:57,571,998 XPM·at block #6,790,997 · updates every 60s