Block #2,699,714

1CCLength 11★★★☆☆

Cunningham Chain of the First Kind · Discovered 6/10/2018, 3:27:28 PM · Difficulty 11.6424 · 4,139,562 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
191ed4a49d42e5ac7632e68e84375ef345b85d83c4b4970c2549e6b0a392f66b

Height

#2,699,714

Difficulty

11.642394

Transactions

4

Size

879 B

Version

2

Bits

0ba473f2

Nonce

737,665,682

Timestamp

6/10/2018, 3:27:28 PM

Confirmations

4,139,562

Merkle Root

117ee062567e68845294342ab0f55e25dde957a67f9b3c0610de7fba232f6f73
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.

6.747 × 10⁹³(94-digit number)
67473118036971637329…84666735061978709319
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
6.747 × 10⁹³(94-digit number)
67473118036971637329…84666735061978709319
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
1.349 × 10⁹⁴(95-digit number)
13494623607394327465…69333470123957418639
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
2.698 × 10⁹⁴(95-digit number)
26989247214788654931…38666940247914837279
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
5.397 × 10⁹⁴(95-digit number)
53978494429577309863…77333880495829674559
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
1.079 × 10⁹⁵(96-digit number)
10795698885915461972…54667760991659349119
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
2.159 × 10⁹⁵(96-digit number)
21591397771830923945…09335521983318698239
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
4.318 × 10⁹⁵(96-digit number)
43182795543661847891…18671043966637396479
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
8.636 × 10⁹⁵(96-digit number)
86365591087323695782…37342087933274792959
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
1.727 × 10⁹⁶(97-digit number)
17273118217464739156…74684175866549585919
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
3.454 × 10⁹⁶(97-digit number)
34546236434929478312…49368351733099171839
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
11
2^10 × origin − 1
6.909 × 10⁹⁶(97-digit number)
69092472869858956625…98736703466198343679
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:57,958,493 XPM·at block #6,839,275 · updates every 60s
xpmprime.info is a work in progress. If you enjoy using this service you can support this project with a Primecoin donation.
Privacy Policy·

Cookie Preferences

We use cookies to enhance your experience. Some are essential for the site to function, while others help us understand how you use the site.

·Privacy Policy