Block #1,111,523

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 6/16/2015, 11:57:48 PM · Difficulty 10.8855 · 5,698,651 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
78f0c3a27e6d8bb83640a25ea14ad26648c9f8a947bf47de4d12e8c8f1c06e03

Height

#1,111,523

Difficulty

10.885480

Transactions

2

Size

1.03 KB

Version

2

Bits

0ae2aecb

Nonce

41,574,075

Timestamp

6/16/2015, 11:57:48 PM

Confirmations

5,698,651

Merkle Root

0768d28108f91c70b77371cc87bd386316cc5fcfbe887e221217e76737e4e5ca
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.

1.517 × 10⁹⁶(97-digit number)
15175033338852245558…97278718581319546881
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
1.517 × 10⁹⁶(97-digit number)
15175033338852245558…97278718581319546881
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
3.035 × 10⁹⁶(97-digit number)
30350066677704491116…94557437162639093761
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
6.070 × 10⁹⁶(97-digit number)
60700133355408982232…89114874325278187521
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
1.214 × 10⁹⁷(98-digit number)
12140026671081796446…78229748650556375041
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
2.428 × 10⁹⁷(98-digit number)
24280053342163592892…56459497301112750081
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
4.856 × 10⁹⁷(98-digit number)
48560106684327185785…12918994602225500161
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
9.712 × 10⁹⁷(98-digit number)
97120213368654371571…25837989204451000321
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
1.942 × 10⁹⁸(99-digit number)
19424042673730874314…51675978408902000641
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
3.884 × 10⁹⁸(99-digit number)
38848085347461748628…03351956817804001281
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
7.769 × 10⁹⁸(99-digit number)
77696170694923497256…06703913635608002561
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 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
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 2CC formula:

2CC: p₁ (first prime), p₂ = 2p₁ − 1, p₃ = 2p₂ − 1, …
Circulating Supply:57,725,460 XPM·at block #6,810,173 · 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.

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