Block #922,313

1CCLength 12★★★★☆

Cunningham Chain of the First Kind · Discovered 2/4/2015, 9:23:42 AM · Difficulty 10.9156 · 5,871,766 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
08d99a27e381dab204f6a340e664eba9542f55895ea0126d2f1e561ebda18473

Height

#922,313

Difficulty

10.915625

Transactions

13

Size

119.46 KB

Version

2

Bits

0aea6664

Nonce

440,319,759

Timestamp

2/4/2015, 9:23:42 AM

Confirmations

5,871,766

Merkle Root

2e5afc09b19574b86a7dc600e7678e6b805c6b43bf3ba85fc1bbdc0d3e413072
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.

3.942 × 10⁹⁷(98-digit number)
39425436069231751093…17115548716419379199
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
3.942 × 10⁹⁷(98-digit number)
39425436069231751093…17115548716419379199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
7.885 × 10⁹⁷(98-digit number)
78850872138463502186…34231097432838758399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
1.577 × 10⁹⁸(99-digit number)
15770174427692700437…68462194865677516799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
3.154 × 10⁹⁸(99-digit number)
31540348855385400874…36924389731355033599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
6.308 × 10⁹⁸(99-digit number)
63080697710770801749…73848779462710067199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
1.261 × 10⁹⁹(100-digit number)
12616139542154160349…47697558925420134399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
2.523 × 10⁹⁹(100-digit number)
25232279084308320699…95395117850840268799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
5.046 × 10⁹⁹(100-digit number)
50464558168616641399…90790235701680537599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
1.009 × 10¹⁰⁰(101-digit number)
10092911633723328279…81580471403361075199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
2.018 × 10¹⁰⁰(101-digit number)
20185823267446656559…63160942806722150399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
11
2^10 × origin − 1
4.037 × 10¹⁰⁰(101-digit number)
40371646534893313119…26321885613444300799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
12
2^11 × origin − 1
8.074 × 10¹⁰⁰(101-digit number)
80743293069786626239…52643771226888601599
Verify on FactorDB ↗Wolfram Alpha ↗

What this block proved

The miner who found this block proved the existence of 12 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
ExceptionalChain length 12

Around 1 in 10,000 blocks. A significant mathematical achievement.

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:57,596,651 XPM·at block #6,794,078 · updates every 60s
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