Block #322,889

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 12/21/2013, 8:10:10 AM · Difficulty 10.1934 · 6,482,325 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
73b90f74c450406910bf9ca99f65bcb1e828515b90540e0c1f80c6b89b51b9d9

Height

#322,889

Difficulty

10.193404

Transactions

16

Size

6.67 KB

Version

2

Bits

0a3182e7

Nonce

245,740

Timestamp

12/21/2013, 8:10:10 AM

Confirmations

6,482,325

Merkle Root

d67a60e83182ec106de80a94d16c95697d58f80fc5ef2a22b86ec420c4677518
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.

1.932 × 10⁹⁷(98-digit number)
19326530401621318730…76361485100908740679
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
1.932 × 10⁹⁷(98-digit number)
19326530401621318730…76361485100908740679
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
3.865 × 10⁹⁷(98-digit number)
38653060803242637460…52722970201817481359
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
7.730 × 10⁹⁷(98-digit number)
77306121606485274921…05445940403634962719
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
1.546 × 10⁹⁸(99-digit number)
15461224321297054984…10891880807269925439
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
3.092 × 10⁹⁸(99-digit number)
30922448642594109968…21783761614539850879
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
6.184 × 10⁹⁸(99-digit number)
61844897285188219936…43567523229079701759
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
1.236 × 10⁹⁹(100-digit number)
12368979457037643987…87135046458159403519
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
2.473 × 10⁹⁹(100-digit number)
24737958914075287974…74270092916318807039
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
4.947 × 10⁹⁹(100-digit number)
49475917828150575949…48540185832637614079
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
9.895 × 10⁹⁹(100-digit number)
98951835656301151898…97080371665275228159
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:57,685,785 XPM·at block #6,805,213 · updates every 60s
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