Block #782,901

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 10/25/2014, 7:52:09 PM · Difficulty 10.9751 · 6,011,849 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
6c039368bf0bbff95a3a30ae0f4a71c45f2e09f48e5be45fdff243bff22a2850

Height

#782,901

Difficulty

10.975066

Transactions

2

Size

15.07 KB

Version

2

Bits

0af99dea

Nonce

533,139,010

Timestamp

10/25/2014, 7:52:09 PM

Confirmations

6,011,849

Merkle Root

8387aa81c79e738f040e6c3d9745f613c6b7b2580258800d9df5bf9757e48996
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.

1.801 × 10⁹⁶(97-digit number)
18016669420551326501…37083275339337411359
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
1.801 × 10⁹⁶(97-digit number)
18016669420551326501…37083275339337411359
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
3.603 × 10⁹⁶(97-digit number)
36033338841102653003…74166550678674822719
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
7.206 × 10⁹⁶(97-digit number)
72066677682205306006…48333101357349645439
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
1.441 × 10⁹⁷(98-digit number)
14413335536441061201…96666202714699290879
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
2.882 × 10⁹⁷(98-digit number)
28826671072882122402…93332405429398581759
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
5.765 × 10⁹⁷(98-digit number)
57653342145764244805…86664810858797163519
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
1.153 × 10⁹⁸(99-digit number)
11530668429152848961…73329621717594327039
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
2.306 × 10⁹⁸(99-digit number)
23061336858305697922…46659243435188654079
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
4.612 × 10⁹⁸(99-digit number)
46122673716611395844…93318486870377308159
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
9.224 × 10⁹⁸(99-digit number)
92245347433222791688…86636973740754616319
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:57,602,052 XPM·at block #6,794,749 · updates every 60s
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