Block #449,089

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 3/18/2014, 9:19:30 AM · Difficulty 10.3673 · 6,351,197 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
4ee7f0e37fcf802e864e5cbd1fa9c6b96fea7b8db31a7a2d4e9c77e5eb1edd08

Height

#449,089

Difficulty

10.367279

Transactions

3

Size

8.60 KB

Version

2

Bits

0a5e05f7

Nonce

434,389

Timestamp

3/18/2014, 9:19:30 AM

Confirmations

6,351,197

Merkle Root

d914e524f5945c8b441fc8290948b94237e5528a28c760ceeaddbdc94c1de887
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.

1.132 × 10⁹⁶(97-digit number)
11321022867600815889…62528046753755427161
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
1.132 × 10⁹⁶(97-digit number)
11321022867600815889…62528046753755427161
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
2.264 × 10⁹⁶(97-digit number)
22642045735201631779…25056093507510854321
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
4.528 × 10⁹⁶(97-digit number)
45284091470403263559…50112187015021708641
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
9.056 × 10⁹⁶(97-digit number)
90568182940806527119…00224374030043417281
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
1.811 × 10⁹⁷(98-digit number)
18113636588161305423…00448748060086834561
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
3.622 × 10⁹⁷(98-digit number)
36227273176322610847…00897496120173669121
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
7.245 × 10⁹⁷(98-digit number)
72454546352645221695…01794992240347338241
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
1.449 × 10⁹⁸(99-digit number)
14490909270529044339…03589984480694676481
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
2.898 × 10⁹⁸(99-digit number)
28981818541058088678…07179968961389352961
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
5.796 × 10⁹⁸(99-digit number)
57963637082116177356…14359937922778705921
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:57,646,348 XPM·at block #6,800,285 · updates every 60s
xpmprime.info is a work in progress. If you enjoy using this service you can support this project with a Primecoin donation.