Block #2,822,148

2CCLength 11★★★☆☆

Cunningham Chain of the Second Kind · Discovered 9/3/2018, 1:09:34 AM · Difficulty 11.7040 · 4,020,579 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
e385e22edb683366e5c22b430d0ffca15bf32e2c776644fef330da52019c83da

Height

#2,822,148

Difficulty

11.703992

Transactions

31

Size

9.53 KB

Version

2

Bits

0bb438d0

Nonce

128,836,527

Timestamp

9/3/2018, 1:09:34 AM

Confirmations

4,020,579

Merkle Root

bf4885b0b3ed945e4b62a3918d174317e8b6ed56fc3ee48dcca29e15fee93f80
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.

7.551 × 10⁹³(94-digit number)
75512451309902238872…88710120771756733601
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
7.551 × 10⁹³(94-digit number)
75512451309902238872…88710120771756733601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
1.510 × 10⁹⁴(95-digit number)
15102490261980447774…77420241543513467201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
3.020 × 10⁹⁴(95-digit number)
30204980523960895549…54840483087026934401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
6.040 × 10⁹⁴(95-digit number)
60409961047921791098…09680966174053868801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
1.208 × 10⁹⁵(96-digit number)
12081992209584358219…19361932348107737601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
2.416 × 10⁹⁵(96-digit number)
24163984419168716439…38723864696215475201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
4.832 × 10⁹⁵(96-digit number)
48327968838337432878…77447729392430950401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
9.665 × 10⁹⁵(96-digit number)
96655937676674865756…54895458784861900801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
1.933 × 10⁹⁶(97-digit number)
19331187535334973151…09790917569723801601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
3.866 × 10⁹⁶(97-digit number)
38662375070669946302…19581835139447603201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
11
2^10 × origin + 1
7.732 × 10⁹⁶(97-digit number)
77324750141339892605…39163670278895206401
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 Second 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 2CC formula:

2CC: p₁ (first prime), p₂ = 2p₁ − 1, p₃ = 2p₂ − 1, …
Circulating Supply:57,986,155 XPM·at block #6,842,726 · updates every 60s
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