Block #445,344

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 3/15/2014, 8:19:25 PM · Difficulty 10.3551 · 6,362,968 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
ed2da9c2f4d7506885b315b9c49efe599c864c2db863cfa1d5fd6d3fe38fe709

Height

#445,344

Difficulty

10.355097

Transactions

3

Size

2.37 KB

Version

2

Bits

0a5ae7a8

Nonce

9,225,542

Timestamp

3/15/2014, 8:19:25 PM

Confirmations

6,362,968

Merkle Root

d123899ce1e6844bcd62afb4521fb45a13ae37de0cbb88a124f895ac427948b1
Transactions (3)
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.

4.353 × 10⁹²(93-digit number)
43536196350947712178…45737289249975500801
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
4.353 × 10⁹²(93-digit number)
43536196350947712178…45737289249975500801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
8.707 × 10⁹²(93-digit number)
87072392701895424356…91474578499951001601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
1.741 × 10⁹³(94-digit number)
17414478540379084871…82949156999902003201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
3.482 × 10⁹³(94-digit number)
34828957080758169742…65898313999804006401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
6.965 × 10⁹³(94-digit number)
69657914161516339485…31796627999608012801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
1.393 × 10⁹⁴(95-digit number)
13931582832303267897…63593255999216025601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
2.786 × 10⁹⁴(95-digit number)
27863165664606535794…27186511998432051201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
5.572 × 10⁹⁴(95-digit number)
55726331329213071588…54373023996864102401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
1.114 × 10⁹⁵(96-digit number)
11145266265842614317…08746047993728204801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
2.229 × 10⁹⁵(96-digit number)
22290532531685228635…17492095987456409601
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 Second 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 2CC formula:

2CC: p₁ (first prime), p₂ = 2p₁ − 1, p₃ = 2p₂ − 1, …
Circulating Supply:57,710,549 XPM·at block #6,808,311 · updates every 60s
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