Block #301,397

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 12/9/2013, 4:15:53 AM · Difficulty 9.9925 · 6,509,080 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
894251f9553b438f1e73a9e1f83e887dd3d4eee3040a84313e877288a265f0e5

Height

#301,397

Difficulty

9.992517

Transactions

15

Size

28.43 KB

Version

2

Bits

09fe1591

Nonce

69,867

Timestamp

12/9/2013, 4:15:53 AM

Confirmations

6,509,080

Merkle Root

9056f30216044711e7b37cc8f3a324f760743fc42dcf9adb116d966933cb5396
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.

6.602 × 10⁹⁷(98-digit number)
66024188429235794163…19594237184134211199
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
6.602 × 10⁹⁷(98-digit number)
66024188429235794163…19594237184134211199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
1.320 × 10⁹⁸(99-digit number)
13204837685847158832…39188474368268422399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
2.640 × 10⁹⁸(99-digit number)
26409675371694317665…78376948736536844799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
5.281 × 10⁹⁸(99-digit number)
52819350743388635330…56753897473073689599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
1.056 × 10⁹⁹(100-digit number)
10563870148677727066…13507794946147379199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
2.112 × 10⁹⁹(100-digit number)
21127740297355454132…27015589892294758399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
4.225 × 10⁹⁹(100-digit number)
42255480594710908264…54031179784589516799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
8.451 × 10⁹⁹(100-digit number)
84510961189421816529…08062359569179033599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
1.690 × 10¹⁰⁰(101-digit number)
16902192237884363305…16124719138358067199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
3.380 × 10¹⁰⁰(101-digit number)
33804384475768726611…32249438276716134399
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 First 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 1CC formula:

1CC: p₁ (first prime), p₂ = 2p₁ + 1, p₃ = 2p₂ + 1, …
Circulating Supply:57,727,895 XPM·at block #6,810,476 · updates every 60s
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