Block #2,287,210

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 9/8/2017, 2:28:03 AM · Difficulty 10.9555 · 4,516,679 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
2ced4c9579b09d402afad0ba981e922469d6783aa2ccb60489e1359a156729e2

Height

#2,287,210

Difficulty

10.955547

Transactions

25

Size

8.66 KB

Version

2

Bits

0af49ec1

Nonce

796,806,755

Timestamp

9/8/2017, 2:28:03 AM

Confirmations

4,516,679

Merkle Root

6de73dd388b34dc2eb3ae7d057aa8bcb97bf4605cf9e18fe54c2de9cfba5d47c
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.

1.411 × 10⁹⁶(97-digit number)
14118307111633603287…13592276158246920319
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
1.411 × 10⁹⁶(97-digit number)
14118307111633603287…13592276158246920319
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
2.823 × 10⁹⁶(97-digit number)
28236614223267206574…27184552316493840639
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
5.647 × 10⁹⁶(97-digit number)
56473228446534413148…54369104632987681279
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
1.129 × 10⁹⁷(98-digit number)
11294645689306882629…08738209265975362559
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
2.258 × 10⁹⁷(98-digit number)
22589291378613765259…17476418531950725119
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
4.517 × 10⁹⁷(98-digit number)
45178582757227530518…34952837063901450239
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
9.035 × 10⁹⁷(98-digit number)
90357165514455061037…69905674127802900479
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
1.807 × 10⁹⁸(99-digit number)
18071433102891012207…39811348255605800959
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
3.614 × 10⁹⁸(99-digit number)
36142866205782024414…79622696511211601919
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
7.228 × 10⁹⁸(99-digit number)
72285732411564048829…59245393022423203839
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:57,675,156 XPM·at block #6,803,888 · updates every 60s
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