Block #429,603

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 3/4/2014, 9:50:07 PM · Difficulty 10.3464 · 6,376,063 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
3eb07e3a5d3aa3f90320f6c6ec6f04fb6d05e35d784103318092608635e8968d

Height

#429,603

Difficulty

10.346412

Transactions

5

Size

1.04 KB

Version

2

Bits

0a58ae74

Nonce

15,760

Timestamp

3/4/2014, 9:50:07 PM

Confirmations

6,376,063

Merkle Root

1af43694345f069d9815f56d78f867055fe398875045ea35e8ade5476c7a2d6d
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.

2.925 × 10⁹⁶(97-digit number)
29259434485057749434…57132945213773362561
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
2.925 × 10⁹⁶(97-digit number)
29259434485057749434…57132945213773362561
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
5.851 × 10⁹⁶(97-digit number)
58518868970115498868…14265890427546725121
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
1.170 × 10⁹⁷(98-digit number)
11703773794023099773…28531780855093450241
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
2.340 × 10⁹⁷(98-digit number)
23407547588046199547…57063561710186900481
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
4.681 × 10⁹⁷(98-digit number)
46815095176092399094…14127123420373800961
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
9.363 × 10⁹⁷(98-digit number)
93630190352184798189…28254246840747601921
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
1.872 × 10⁹⁸(99-digit number)
18726038070436959637…56508493681495203841
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
3.745 × 10⁹⁸(99-digit number)
37452076140873919275…13016987362990407681
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
7.490 × 10⁹⁸(99-digit number)
74904152281747838551…26033974725980815361
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
1.498 × 10⁹⁹(100-digit number)
14980830456349567710…52067949451961630721
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:57,689,406 XPM·at block #6,805,665 · updates every 60s
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