Block #2,133,299

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 5/26/2017, 10:05:30 AM · Difficulty 10.9098 · 4,709,669 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
4b4e6415e5924fd41844aa75a4eb5282e8e09f7af48ccca0f6177af827213cc9

Height

#2,133,299

Difficulty

10.909810

Transactions

4

Size

1.62 KB

Version

2

Bits

0ae8e949

Nonce

244,377,025

Timestamp

5/26/2017, 10:05:30 AM

Confirmations

4,709,669

Merkle Root

f7fc2e27009d1c4f5ad192b872c742b531752663c178fc34ed598c3ca54434cb
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.

1.211 × 10⁹³(94-digit number)
12112100276857433002…16611621671191984639
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
1.211 × 10⁹³(94-digit number)
12112100276857433002…16611621671191984639
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
2.422 × 10⁹³(94-digit number)
24224200553714866005…33223243342383969279
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
4.844 × 10⁹³(94-digit number)
48448401107429732010…66446486684767938559
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
9.689 × 10⁹³(94-digit number)
96896802214859464020…32892973369535877119
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
1.937 × 10⁹⁴(95-digit number)
19379360442971892804…65785946739071754239
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
3.875 × 10⁹⁴(95-digit number)
38758720885943785608…31571893478143508479
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
7.751 × 10⁹⁴(95-digit number)
77517441771887571216…63143786956287016959
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
1.550 × 10⁹⁵(96-digit number)
15503488354377514243…26287573912574033919
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
3.100 × 10⁹⁵(96-digit number)
31006976708755028486…52575147825148067839
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
6.201 × 10⁹⁵(96-digit number)
62013953417510056973…05150295650296135679
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:57,988,096 XPM·at block #6,842,967 · updates every 60s
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