Block #466,525

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 3/30/2014, 5:52:35 AM · Difficulty 10.4213 · 6,335,288 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
696812eae56c43afd5ccc7c39ad2f120fedd455bc45fb54d5d3eebd65818f882

Height

#466,525

Difficulty

10.421312

Transactions

9

Size

2.02 KB

Version

2

Bits

0a6bdb20

Nonce

12,330

Timestamp

3/30/2014, 5:52:35 AM

Confirmations

6,335,288

Merkle Root

3f09c10a8f25066f07efda14b723dd4090bcf5f49ecfd7aba86a89253f884295
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.

7.341 × 10¹⁰²(103-digit number)
73419891550307073415…92019721429617643521
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
7.341 × 10¹⁰²(103-digit number)
73419891550307073415…92019721429617643521
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
1.468 × 10¹⁰³(104-digit number)
14683978310061414683…84039442859235287041
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
2.936 × 10¹⁰³(104-digit number)
29367956620122829366…68078885718470574081
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
5.873 × 10¹⁰³(104-digit number)
58735913240245658732…36157771436941148161
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
1.174 × 10¹⁰⁴(105-digit number)
11747182648049131746…72315542873882296321
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
2.349 × 10¹⁰⁴(105-digit number)
23494365296098263493…44631085747764592641
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
4.698 × 10¹⁰⁴(105-digit number)
46988730592196526986…89262171495529185281
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
9.397 × 10¹⁰⁴(105-digit number)
93977461184393053972…78524342991058370561
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
1.879 × 10¹⁰⁵(106-digit number)
18795492236878610794…57048685982116741121
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
3.759 × 10¹⁰⁵(106-digit number)
37590984473757221588…14097371964233482241
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:57,658,596 XPM·at block #6,801,812 · updates every 60s
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