Block #554,031

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 5/20/2014, 1:24:37 PM · Difficulty 10.9631 · 6,249,456 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
4110a0d62983154671054ba286014b2b0dfdb497ee6c5ef85696555084776794

Height

#554,031

Difficulty

10.963133

Transactions

7

Size

1.67 KB

Version

2

Bits

0af68fdb

Nonce

873,585,140

Timestamp

5/20/2014, 1:24:37 PM

Confirmations

6,249,456

Merkle Root

3dded058244fce7b4383921ec89685d3e218a9aed4657888a8afdc5cea53b62e
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.

8.270 × 10⁹⁷(98-digit number)
82704572771959577970…16262699753119404649
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
8.270 × 10⁹⁷(98-digit number)
82704572771959577970…16262699753119404649
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
1.654 × 10⁹⁸(99-digit number)
16540914554391915594…32525399506238809299
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
3.308 × 10⁹⁸(99-digit number)
33081829108783831188…65050799012477618599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
6.616 × 10⁹⁸(99-digit number)
66163658217567662376…30101598024955237199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
1.323 × 10⁹⁹(100-digit number)
13232731643513532475…60203196049910474399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
2.646 × 10⁹⁹(100-digit number)
26465463287027064950…20406392099820948799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
5.293 × 10⁹⁹(100-digit number)
52930926574054129900…40812784199641897599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
1.058 × 10¹⁰⁰(101-digit number)
10586185314810825980…81625568399283795199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
2.117 × 10¹⁰⁰(101-digit number)
21172370629621651960…63251136798567590399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
4.234 × 10¹⁰⁰(101-digit number)
42344741259243303920…26502273597135180799
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:57,671,927 XPM·at block #6,803,486 · updates every 60s
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