Block #2,692,166

1CCLength 11★★★☆☆

Cunningham Chain of the First Kind · Discovered 6/4/2018, 11:16:00 PM · Difficulty 11.6837 · 4,151,874 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
e3cf67b9523ae9298b255e4eb3a18bf103dc57067cc46142a0dda424a37e256b

Height

#2,692,166

Difficulty

11.683663

Transactions

17

Size

5.12 KB

Version

2

Bits

0baf0492

Nonce

1,197,719,530

Timestamp

6/4/2018, 11:16:00 PM

Confirmations

4,151,874

Merkle Root

f49953bc2c42c94472a691f2c2f4b9bc21b1657a24018974ca313a5e71c82b76
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.

1.450 × 10⁹⁶(97-digit number)
14508201276490927777…50923213369777447679
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
1.450 × 10⁹⁶(97-digit number)
14508201276490927777…50923213369777447679
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
2.901 × 10⁹⁶(97-digit number)
29016402552981855554…01846426739554895359
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
5.803 × 10⁹⁶(97-digit number)
58032805105963711109…03692853479109790719
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
1.160 × 10⁹⁷(98-digit number)
11606561021192742221…07385706958219581439
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
2.321 × 10⁹⁷(98-digit number)
23213122042385484443…14771413916439162879
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
4.642 × 10⁹⁷(98-digit number)
46426244084770968887…29542827832878325759
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
9.285 × 10⁹⁷(98-digit number)
92852488169541937775…59085655665756651519
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
1.857 × 10⁹⁸(99-digit number)
18570497633908387555…18171311331513303039
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
3.714 × 10⁹⁸(99-digit number)
37140995267816775110…36342622663026606079
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
7.428 × 10⁹⁸(99-digit number)
74281990535633550220…72685245326053212159
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
11
2^10 × origin − 1
1.485 × 10⁹⁹(100-digit number)
14856398107126710044…45370490652106424319
Verify on FactorDB ↗Wolfram Alpha ↗

What this block proved

The miner who found this block proved the existence of 11 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
RareChain length 11

Approximately 1 in 1,000 blocks. Noteworthy discoveries.

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:57,996,689 XPM·at block #6,844,039 · updates every 60s
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