Block #1,441,544

2CCLength 11★★★☆☆

Cunningham Chain of the Second Kind · Discovered 2/4/2016, 1:14:17 AM · Difficulty 10.7609 · 5,383,361 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
3235a9402bdb0899d0a9a85fa75a6a6692c8d49854b549b808e69afd6b7df2c0

Height

#1,441,544

Difficulty

10.760852

Transactions

54

Size

23.80 KB

Version

2

Bits

0ac2c738

Nonce

48,620,321

Timestamp

2/4/2016, 1:14:17 AM

Confirmations

5,383,361

Merkle Root

171e214529f0e1d291f737d3d9c9d7fdf3f1ae3f2156f79be69ec98f78f7da94
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.

2.712 × 10⁹⁵(96-digit number)
27126180833856831910…26151631366047629761
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
2.712 × 10⁹⁵(96-digit number)
27126180833856831910…26151631366047629761
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
5.425 × 10⁹⁵(96-digit number)
54252361667713663821…52303262732095259521
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
1.085 × 10⁹⁶(97-digit number)
10850472333542732764…04606525464190519041
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
2.170 × 10⁹⁶(97-digit number)
21700944667085465528…09213050928381038081
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
4.340 × 10⁹⁶(97-digit number)
43401889334170931057…18426101856762076161
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
8.680 × 10⁹⁶(97-digit number)
86803778668341862114…36852203713524152321
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
1.736 × 10⁹⁷(98-digit number)
17360755733668372422…73704407427048304641
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
3.472 × 10⁹⁷(98-digit number)
34721511467336744845…47408814854096609281
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
6.944 × 10⁹⁷(98-digit number)
69443022934673489691…94817629708193218561
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
1.388 × 10⁹⁸(99-digit number)
13888604586934697938…89635259416386437121
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
11
2^10 × origin + 1
2.777 × 10⁹⁸(99-digit number)
27777209173869395876…79270518832772874241
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:57,843,323 XPM·at block #6,824,904 · updates every 60s
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