Block #454,487

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 3/21/2014, 11:15:23 PM · Difficulty 10.3996 · 6,363,458 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
fd876d9f9dfad351cd1e0050e90c516a22eeec4dce7f7364cfd9bd778ed46cb4

Height

#454,487

Difficulty

10.399616

Transactions

4

Size

3.04 KB

Version

2

Bits

0a664d41

Nonce

6,301,789

Timestamp

3/21/2014, 11:15:23 PM

Confirmations

6,363,458

Merkle Root

15644a68ba8d0c576f77d8f285e1b863cac1d55741a26d33ec25bae651a9cdf7
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.

6.652 × 10⁹⁴(95-digit number)
66529674787023176795…85725034657493664161
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
6.652 × 10⁹⁴(95-digit number)
66529674787023176795…85725034657493664161
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
1.330 × 10⁹⁵(96-digit number)
13305934957404635359…71450069314987328321
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
2.661 × 10⁹⁵(96-digit number)
26611869914809270718…42900138629974656641
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
5.322 × 10⁹⁵(96-digit number)
53223739829618541436…85800277259949313281
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
1.064 × 10⁹⁶(97-digit number)
10644747965923708287…71600554519898626561
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
2.128 × 10⁹⁶(97-digit number)
21289495931847416574…43201109039797253121
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
4.257 × 10⁹⁶(97-digit number)
42578991863694833149…86402218079594506241
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
8.515 × 10⁹⁶(97-digit number)
85157983727389666298…72804436159189012481
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
1.703 × 10⁹⁷(98-digit number)
17031596745477933259…45608872318378024961
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
3.406 × 10⁹⁷(98-digit number)
34063193490955866519…91217744636756049921
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:57,787,627 XPM·at block #6,817,944 · updates every 60s
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