Block #457,870

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 3/24/2014, 4:58:35 AM · Difficulty 10.4209 · 6,336,228 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
3d061f8e4e992a0188b0a99a96ff7879fd7c2509eedf481d69dd4e106bb1c1f2

Height

#457,870

Difficulty

10.420893

Transactions

15

Size

11.54 KB

Version

2

Bits

0a6bbf9f

Nonce

115,368

Timestamp

3/24/2014, 4:58:35 AM

Confirmations

6,336,228

Merkle Root

26e1cc55bdb1e8391f603c5b271786594078dfddfd9978b9b32ba23d7d517c38
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.

3.957 × 10⁹⁵(96-digit number)
39579532161041300902…22927640096815184541
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
3.957 × 10⁹⁵(96-digit number)
39579532161041300902…22927640096815184541
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
7.915 × 10⁹⁵(96-digit number)
79159064322082601805…45855280193630369081
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
1.583 × 10⁹⁶(97-digit number)
15831812864416520361…91710560387260738161
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
3.166 × 10⁹⁶(97-digit number)
31663625728833040722…83421120774521476321
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
6.332 × 10⁹⁶(97-digit number)
63327251457666081444…66842241549042952641
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
1.266 × 10⁹⁷(98-digit number)
12665450291533216288…33684483098085905281
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
2.533 × 10⁹⁷(98-digit number)
25330900583066432577…67368966196171810561
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
5.066 × 10⁹⁷(98-digit number)
50661801166132865155…34737932392343621121
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
1.013 × 10⁹⁸(99-digit number)
10132360233226573031…69475864784687242241
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
2.026 × 10⁹⁸(99-digit number)
20264720466453146062…38951729569374484481
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:57,596,806 XPM·at block #6,794,097 · updates every 60s
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