Block #456,577

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 3/23/2014, 7:54:06 AM · Difficulty 10.4168 · 6,346,788 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
402cf0c3fc8aa7db6f98c1e069004be41dab40796b4d1a26a7d75b451d192028

Height

#456,577

Difficulty

10.416782

Transactions

3

Size

1.29 KB

Version

2

Bits

0a6ab23f

Nonce

48,088

Timestamp

3/23/2014, 7:54:06 AM

Confirmations

6,346,788

Merkle Root

fca9708649e481f6ba95d64777db186eb0ec1c4d58ddadd64fef9d0d9f3613ca
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.

1.600 × 10⁹⁷(98-digit number)
16009155452402636746…11539984108362062051
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
1.600 × 10⁹⁷(98-digit number)
16009155452402636746…11539984108362062051
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
3.201 × 10⁹⁷(98-digit number)
32018310904805273493…23079968216724124101
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
6.403 × 10⁹⁷(98-digit number)
64036621809610546987…46159936433448248201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
1.280 × 10⁹⁸(99-digit number)
12807324361922109397…92319872866896496401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
2.561 × 10⁹⁸(99-digit number)
25614648723844218794…84639745733792992801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
5.122 × 10⁹⁸(99-digit number)
51229297447688437589…69279491467585985601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
1.024 × 10⁹⁹(100-digit number)
10245859489537687517…38558982935171971201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
2.049 × 10⁹⁹(100-digit number)
20491718979075375035…77117965870343942401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
4.098 × 10⁹⁹(100-digit number)
40983437958150750071…54235931740687884801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
8.196 × 10⁹⁹(100-digit number)
81966875916301500143…08471863481375769601
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:57,670,957 XPM·at block #6,803,364 · updates every 60s
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