Block #456,888

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 3/23/2014, 12:59:09 PM · Difficulty 10.4177 · 6,352,807 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
7aad6285d84232538d3443a6c21beac0bb15034856641552747cbc7abf9a8391

Height

#456,888

Difficulty

10.417737

Transactions

2

Size

675 B

Version

2

Bits

0a6af0d7

Nonce

1,355,302,530

Timestamp

3/23/2014, 12:59:09 PM

Confirmations

6,352,807

Merkle Root

2aa10074bf5a0737221ed292994fd37e76263360f5bf70e76ac81361a0d7fdc2
Transactions (2)
1 in → 1 out9.2100 XPM89 B
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.

6.365 × 10¹¹⁰(111-digit number)
63656260033189808578…79519945643227381761
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
6.365 × 10¹¹⁰(111-digit number)
63656260033189808578…79519945643227381761
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
1.273 × 10¹¹¹(112-digit number)
12731252006637961715…59039891286454763521
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
2.546 × 10¹¹¹(112-digit number)
25462504013275923431…18079782572909527041
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
5.092 × 10¹¹¹(112-digit number)
50925008026551846862…36159565145819054081
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
1.018 × 10¹¹²(113-digit number)
10185001605310369372…72319130291638108161
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
2.037 × 10¹¹²(113-digit number)
20370003210620738744…44638260583276216321
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
4.074 × 10¹¹²(113-digit number)
40740006421241477489…89276521166552432641
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
8.148 × 10¹¹²(113-digit number)
81480012842482954979…78553042333104865281
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
1.629 × 10¹¹³(114-digit number)
16296002568496590995…57106084666209730561
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
3.259 × 10¹¹³(114-digit number)
32592005136993181991…14212169332419461121
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:57,721,637 XPM·at block #6,809,694 · updates every 60s
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