Block #430,839

2CCLength 11★★★☆☆

Cunningham Chain of the Second Kind · Discovered 3/5/2014, 6:27:01 PM · Difficulty 10.3468 · 6,369,763 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
cbfd1cbe7e6c44fce27fc6ff5303f2cf2b57fd0496cf67820daa703e73767f24

Height

#430,839

Difficulty

10.346783

Transactions

5

Size

1.47 KB

Version

2

Bits

0a58c6ca

Nonce

245,864

Timestamp

3/5/2014, 6:27:01 PM

Confirmations

6,369,763

Merkle Root

aecca95dd15aea955ce2f3db571efeee3e22f537984fbba93e88c25e020b7d6a
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.

1.345 × 10¹⁰⁰(101-digit number)
13454420238616805529…05273152950451051681
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
1.345 × 10¹⁰⁰(101-digit number)
13454420238616805529…05273152950451051681
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
2.690 × 10¹⁰⁰(101-digit number)
26908840477233611058…10546305900902103361
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
5.381 × 10¹⁰⁰(101-digit number)
53817680954467222117…21092611801804206721
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
1.076 × 10¹⁰¹(102-digit number)
10763536190893444423…42185223603608413441
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
2.152 × 10¹⁰¹(102-digit number)
21527072381786888846…84370447207216826881
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
4.305 × 10¹⁰¹(102-digit number)
43054144763573777693…68740894414433653761
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
8.610 × 10¹⁰¹(102-digit number)
86108289527147555387…37481788828867307521
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
1.722 × 10¹⁰²(103-digit number)
17221657905429511077…74963577657734615041
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
3.444 × 10¹⁰²(103-digit number)
34443315810859022155…49927155315469230081
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
6.888 × 10¹⁰²(103-digit number)
68886631621718044310…99854310630938460161
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
11
2^10 × origin + 1
1.377 × 10¹⁰³(104-digit number)
13777326324343608862…99708621261876920321
Verify on FactorDB ↗Wolfram Alpha ↗

What this block proved

The miner who found this block proved the existence of 11 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
RareChain length 11

Approximately 1 in 1,000 blocks. Noteworthy discoveries.

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:57,648,876 XPM·at block #6,800,601 · updates every 60s
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