Block #111,993

1CCLength 9★☆☆☆☆

Cunningham Chain of the First Kind · Discovered 8/11/2013, 6:30:01 PM · Difficulty 9.7147 · 6,679,011 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
168853944d95b67f8fd129d5a98ccdbdae142dfec59fa268933227ae838e6455

Height

#111,993

Difficulty

9.714722

Transactions

3

Size

46.18 KB

Version

2

Bits

09b6f801

Nonce

25,852

Timestamp

8/11/2013, 6:30:01 PM

Confirmations

6,679,011

Merkle Root

d3b564f2efd243877f161145a098e173f0ba6652062c462f5b19c1db42644f4a
Transactions (3)
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.

1.096 × 10¹⁰²(103-digit number)
10962906744448211597…63788425896522420519
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
1.096 × 10¹⁰²(103-digit number)
10962906744448211597…63788425896522420519
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
2.192 × 10¹⁰²(103-digit number)
21925813488896423195…27576851793044841039
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
4.385 × 10¹⁰²(103-digit number)
43851626977792846391…55153703586089682079
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
8.770 × 10¹⁰²(103-digit number)
87703253955585692782…10307407172179364159
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
1.754 × 10¹⁰³(104-digit number)
17540650791117138556…20614814344358728319
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
3.508 × 10¹⁰³(104-digit number)
35081301582234277113…41229628688717456639
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
7.016 × 10¹⁰³(104-digit number)
70162603164468554226…82459257377434913279
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
1.403 × 10¹⁰⁴(105-digit number)
14032520632893710845…64918514754869826559
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
2.806 × 10¹⁰⁴(105-digit number)
28065041265787421690…29837029509739653119
Verify on FactorDB ↗Wolfram Alpha ↗

What this block proved

The miner who found this block proved the existence of 9 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
CommonChain length 9

Found in most blocks. The baseline for Primecoin's proof-of-work.

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:57,572,047 XPM·at block #6,791,003 · updates every 60s