Block #466,573

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 3/30/2014, 6:35:30 AM · Difficulty 10.4216 · 6,326,090 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
2973b8e2f6497f201e9fcd3a8208f021b3ffb026a86c3a7e8b151a6abe642971

Height

#466,573

Difficulty

10.421575

Transactions

6

Size

7.28 KB

Version

2

Bits

0a6bec55

Nonce

20,116

Timestamp

3/30/2014, 6:35:30 AM

Confirmations

6,326,090

Merkle Root

5836ed7fbaf9f4fb0a7dbf0ca80052f74c1d06fa106945a381e2a7e2279ac2a7
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.

1.087 × 10⁹⁸(99-digit number)
10874790784259100755…01587870975000606001
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
1.087 × 10⁹⁸(99-digit number)
10874790784259100755…01587870975000606001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
2.174 × 10⁹⁸(99-digit number)
21749581568518201511…03175741950001212001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
4.349 × 10⁹⁸(99-digit number)
43499163137036403022…06351483900002424001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
8.699 × 10⁹⁸(99-digit number)
86998326274072806044…12702967800004848001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
1.739 × 10⁹⁹(100-digit number)
17399665254814561208…25405935600009696001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
3.479 × 10⁹⁹(100-digit number)
34799330509629122417…50811871200019392001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
6.959 × 10⁹⁹(100-digit number)
69598661019258244835…01623742400038784001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
1.391 × 10¹⁰⁰(101-digit number)
13919732203851648967…03247484800077568001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
2.783 × 10¹⁰⁰(101-digit number)
27839464407703297934…06494969600155136001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
5.567 × 10¹⁰⁰(101-digit number)
55678928815406595868…12989939200310272001
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:57,585,274 XPM·at block #6,792,662 · updates every 60s
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