Block #784,164

1CCLength 11★★★☆☆

Cunningham Chain of the First Kind · Discovered 10/26/2014, 4:50:54 PM · Difficulty 10.9751 · 6,018,389 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
d1485d9d1447eba14776c56341a4c794ba0c436c38cdc8545ba66fd5651a7a4a

Height

#784,164

Difficulty

10.975125

Transactions

2

Size

12.91 KB

Version

2

Bits

0af9a1c3

Nonce

206,032,510

Timestamp

10/26/2014, 4:50:54 PM

Confirmations

6,018,389

Merkle Root

a9a8887d7055e3346f20ccd9b568b71862360e110c3b22aa6ef1651e5ee1072c
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.

2.853 × 10⁹⁵(96-digit number)
28532916288727615642…49077190036682162209
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
2.853 × 10⁹⁵(96-digit number)
28532916288727615642…49077190036682162209
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
5.706 × 10⁹⁵(96-digit number)
57065832577455231285…98154380073364324419
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
1.141 × 10⁹⁶(97-digit number)
11413166515491046257…96308760146728648839
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
2.282 × 10⁹⁶(97-digit number)
22826333030982092514…92617520293457297679
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
4.565 × 10⁹⁶(97-digit number)
45652666061964185028…85235040586914595359
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
9.130 × 10⁹⁶(97-digit number)
91305332123928370057…70470081173829190719
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
1.826 × 10⁹⁷(98-digit number)
18261066424785674011…40940162347658381439
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
3.652 × 10⁹⁷(98-digit number)
36522132849571348022…81880324695316762879
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
7.304 × 10⁹⁷(98-digit number)
73044265699142696045…63760649390633525759
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
1.460 × 10⁹⁸(99-digit number)
14608853139828539209…27521298781267051519
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
11
2^10 × origin − 1
2.921 × 10⁹⁸(99-digit number)
29217706279657078418…55042597562534103039
Verify on FactorDB ↗Wolfram Alpha ↗

What this block proved

The miner who found this block proved the existence of 11 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
RareChain length 11

Approximately 1 in 1,000 blocks. Noteworthy discoveries.

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:57,664,437 XPM·at block #6,802,552 · updates every 60s
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