Block #112,801

1CCLength 9★☆☆☆☆

Cunningham Chain of the First Kind · Discovered 8/12/2013, 4:34:26 AM · Difficulty 9.7259 · 6,678,354 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
cf275c93c2d662baae636c0cbe8daf821ab2d08c3dae9e54ffd30d86d01a7123

Height

#112,801

Difficulty

9.725922

Transactions

2

Size

424 B

Version

2

Bits

09b9d606

Nonce

21,804

Timestamp

8/12/2013, 4:34:26 AM

Confirmations

6,678,354

Merkle Root

367a55e28f14a96d09b2fa8a366ad9fc2719365d7633961939534ae03cbb7197
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.

3.344 × 10⁹⁴(95-digit number)
33447320729995211794…61550334045753215859
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
3.344 × 10⁹⁴(95-digit number)
33447320729995211794…61550334045753215859
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
6.689 × 10⁹⁴(95-digit number)
66894641459990423588…23100668091506431719
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
1.337 × 10⁹⁵(96-digit number)
13378928291998084717…46201336183012863439
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
2.675 × 10⁹⁵(96-digit number)
26757856583996169435…92402672366025726879
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
5.351 × 10⁹⁵(96-digit number)
53515713167992338870…84805344732051453759
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
1.070 × 10⁹⁶(97-digit number)
10703142633598467774…69610689464102907519
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
2.140 × 10⁹⁶(97-digit number)
21406285267196935548…39221378928205815039
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
4.281 × 10⁹⁶(97-digit number)
42812570534393871096…78442757856411630079
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
8.562 × 10⁹⁶(97-digit number)
85625141068787742192…56885515712823260159
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:57,573,179 XPM·at block #6,791,154 · updates every 60s
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