Block #333,930

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 12/29/2013, 3:35:57 AM · Difficulty 10.1594 · 6,461,042 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
b43b757da64a50148478a3caab3d8298f0e5c2110144a1ef6a402f58415988b6

Height

#333,930

Difficulty

10.159405

Transactions

24

Size

14.80 KB

Version

2

Bits

0a28cec7

Nonce

42,160

Timestamp

12/29/2013, 3:35:57 AM

Confirmations

6,461,042

Merkle Root

e92680576f44094f0fa3000b8376a0640ada2871374338b47d8c06c1d439e2a7
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.

3.641 × 10⁹⁸(99-digit number)
36413594746453901966…72383538438368355201
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
3.641 × 10⁹⁸(99-digit number)
36413594746453901966…72383538438368355201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
7.282 × 10⁹⁸(99-digit number)
72827189492907803932…44767076876736710401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
1.456 × 10⁹⁹(100-digit number)
14565437898581560786…89534153753473420801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
2.913 × 10⁹⁹(100-digit number)
29130875797163121573…79068307506946841601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
5.826 × 10⁹⁹(100-digit number)
58261751594326243146…58136615013893683201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
1.165 × 10¹⁰⁰(101-digit number)
11652350318865248629…16273230027787366401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
2.330 × 10¹⁰⁰(101-digit number)
23304700637730497258…32546460055574732801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
4.660 × 10¹⁰⁰(101-digit number)
46609401275460994516…65092920111149465601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
9.321 × 10¹⁰⁰(101-digit number)
93218802550921989033…30185840222298931201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
1.864 × 10¹⁰¹(102-digit number)
18643760510184397806…60371680444597862401
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:57,603,815 XPM·at block #6,794,971 · updates every 60s
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