Block #113,112

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 8/12/2013, 8:47:33 AM · Difficulty 9.7291 · 6,680,083 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
d7bf0640649324c9d329ed27f2593c1b4db21563950a6b8332e2b62e859fafd2

Height

#113,112

Difficulty

9.729133

Transactions

1

Size

200 B

Version

2

Bits

09baa872

Nonce

613,721

Timestamp

8/12/2013, 8:47:33 AM

Confirmations

6,680,083

Merkle Root

df2579ccee0e9f0acf88246d1dd5359631fabda0850ffb58e59cfbcf442bdcae
Transactions (1)
1 in → 1 out10.5500 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.

1.344 × 10⁹⁶(97-digit number)
13446743407096832598…42095095913617019169
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
1.344 × 10⁹⁶(97-digit number)
13446743407096832598…42095095913617019169
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
2.689 × 10⁹⁶(97-digit number)
26893486814193665196…84190191827234038339
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
5.378 × 10⁹⁶(97-digit number)
53786973628387330393…68380383654468076679
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
1.075 × 10⁹⁷(98-digit number)
10757394725677466078…36760767308936153359
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
2.151 × 10⁹⁷(98-digit number)
21514789451354932157…73521534617872306719
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
4.302 × 10⁹⁷(98-digit number)
43029578902709864314…47043069235744613439
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
8.605 × 10⁹⁷(98-digit number)
86059157805419728629…94086138471489226879
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
1.721 × 10⁹⁸(99-digit number)
17211831561083945725…88172276942978453759
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
3.442 × 10⁹⁸(99-digit number)
34423663122167891451…76344553885956907519
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
6.884 × 10⁹⁸(99-digit number)
68847326244335782903…52689107771913815039
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:57,589,555 XPM·at block #6,793,194 · updates every 60s
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