Block #322,837

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 12/21/2013, 7:06:31 AM · Difficulty 10.1919 · 6,480,625 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
829bda39b6cbf119762e3d12309e2a8362d4fbe99bcfe22563f53aea7ca2d182

Height

#322,837

Difficulty

10.191906

Transactions

26

Size

10.47 KB

Version

2

Bits

0a3120bc

Nonce

71,269

Timestamp

12/21/2013, 7:06:31 AM

Confirmations

6,480,625

Merkle Root

7e7d1051c6db31c89b483741bd28716eb77b5865a498c0ba079e42e9f01c0fd2
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.

1.829 × 10⁹⁴(95-digit number)
18290990888971722227…07749558549678233599
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
1.829 × 10⁹⁴(95-digit number)
18290990888971722227…07749558549678233599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
3.658 × 10⁹⁴(95-digit number)
36581981777943444454…15499117099356467199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
7.316 × 10⁹⁴(95-digit number)
73163963555886888909…30998234198712934399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
1.463 × 10⁹⁵(96-digit number)
14632792711177377781…61996468397425868799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
2.926 × 10⁹⁵(96-digit number)
29265585422354755563…23992936794851737599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
5.853 × 10⁹⁵(96-digit number)
58531170844709511127…47985873589703475199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
1.170 × 10⁹⁶(97-digit number)
11706234168941902225…95971747179406950399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
2.341 × 10⁹⁶(97-digit number)
23412468337883804450…91943494358813900799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
4.682 × 10⁹⁶(97-digit number)
46824936675767608901…83886988717627801599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
9.364 × 10⁹⁶(97-digit number)
93649873351535217803…67773977435255603199
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:57,671,724 XPM·at block #6,803,461 · updates every 60s
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