Block #1,144,691

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 7/8/2015, 10:53:20 AM · Difficulty 10.9281 · 5,649,893 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
3c59b1f912d5be907ada0ed6170544657d539827d641fc2f48ddaf2872c903b2

Height

#1,144,691

Difficulty

10.928123

Transactions

6

Size

1.88 KB

Version

2

Bits

0aed9973

Nonce

1,123,796,471

Timestamp

7/8/2015, 10:53:20 AM

Confirmations

5,649,893

Merkle Root

7eb0851cffa2fc69aeb0474bdd25e7d3011f3bd4cacec2f50adb265202dd0478
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.

7.466 × 10⁹³(94-digit number)
74666764242557631542…40937481023760236459
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
7.466 × 10⁹³(94-digit number)
74666764242557631542…40937481023760236459
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
1.493 × 10⁹⁴(95-digit number)
14933352848511526308…81874962047520472919
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
2.986 × 10⁹⁴(95-digit number)
29866705697023052617…63749924095040945839
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
5.973 × 10⁹⁴(95-digit number)
59733411394046105234…27499848190081891679
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
1.194 × 10⁹⁵(96-digit number)
11946682278809221046…54999696380163783359
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
2.389 × 10⁹⁵(96-digit number)
23893364557618442093…09999392760327566719
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
4.778 × 10⁹⁵(96-digit number)
47786729115236884187…19998785520655133439
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
9.557 × 10⁹⁵(96-digit number)
95573458230473768374…39997571041310266879
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
1.911 × 10⁹⁶(97-digit number)
19114691646094753674…79995142082620533759
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
3.822 × 10⁹⁶(97-digit number)
38229383292189507349…59990284165241067519
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:57,600,719 XPM·at block #6,794,583 · updates every 60s
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