Block #440,894

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 3/12/2014, 5:57:47 PM · Difficulty 10.3530 · 6,362,170 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
95effd40abce3a11da306c77f6ac91a3bea86d269b11f0b3a10ef3d172f1274f

Height

#440,894

Difficulty

10.353015

Transactions

4

Size

1.52 KB

Version

2

Bits

0a5a5f37

Nonce

5,611

Timestamp

3/12/2014, 5:57:47 PM

Confirmations

6,362,170

Merkle Root

bd5b5212c170570205f4f2d3b666daaeffd6116383d0df5101ca69adf6b37a37
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.

2.384 × 10⁹⁷(98-digit number)
23841798890789269439…70107390214566342319
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
2.384 × 10⁹⁷(98-digit number)
23841798890789269439…70107390214566342319
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
4.768 × 10⁹⁷(98-digit number)
47683597781578538879…40214780429132684639
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
9.536 × 10⁹⁷(98-digit number)
95367195563157077759…80429560858265369279
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
1.907 × 10⁹⁸(99-digit number)
19073439112631415551…60859121716530738559
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
3.814 × 10⁹⁸(99-digit number)
38146878225262831103…21718243433061477119
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
7.629 × 10⁹⁸(99-digit number)
76293756450525662207…43436486866122954239
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
1.525 × 10⁹⁹(100-digit number)
15258751290105132441…86872973732245908479
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
3.051 × 10⁹⁹(100-digit number)
30517502580210264882…73745947464491816959
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
6.103 × 10⁹⁹(100-digit number)
61035005160420529765…47491894928983633919
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
1.220 × 10¹⁰⁰(101-digit number)
12207001032084105953…94983789857967267839
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:57,668,540 XPM·at block #6,803,063 · updates every 60s
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