Block #679,324

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 8/15/2014, 9:24:52 PM · Difficulty 10.9632 · 6,115,438 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
8b9900a845949255fd5f6693f6dded62cccdd24df87efe583b84cefcc4cffdb6

Height

#679,324

Difficulty

10.963150

Transactions

9

Size

1.97 KB

Version

2

Bits

0af69101

Nonce

17,591,966

Timestamp

8/15/2014, 9:24:52 PM

Confirmations

6,115,438

Merkle Root

06c4935edc144c37784792d585271bf861c891c176d8b22d1ae64629c5755227
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.

2.648 × 10⁹⁵(96-digit number)
26485342929963738762…26379815526584387249
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
2.648 × 10⁹⁵(96-digit number)
26485342929963738762…26379815526584387249
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
5.297 × 10⁹⁵(96-digit number)
52970685859927477524…52759631053168774499
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
1.059 × 10⁹⁶(97-digit number)
10594137171985495504…05519262106337548999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
2.118 × 10⁹⁶(97-digit number)
21188274343970991009…11038524212675097999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
4.237 × 10⁹⁶(97-digit number)
42376548687941982019…22077048425350195999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
8.475 × 10⁹⁶(97-digit number)
84753097375883964038…44154096850700391999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
1.695 × 10⁹⁷(98-digit number)
16950619475176792807…88308193701400783999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
3.390 × 10⁹⁷(98-digit number)
33901238950353585615…76616387402801567999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
6.780 × 10⁹⁷(98-digit number)
67802477900707171230…53232774805603135999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
1.356 × 10⁹⁸(99-digit number)
13560495580141434246…06465549611206271999
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:57,602,144 XPM·at block #6,794,761 · updates every 60s
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