Block #1,458,794

2CCLength 11★★★☆☆

Cunningham Chain of the Second Kind · Discovered 2/15/2016, 10:04:05 PM · Difficulty 10.7687 · 5,384,661 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
b42231b06c367c37837b12f3f0e5dcd2daf981e7f631d43a72587f1f74223994

Height

#1,458,794

Difficulty

10.768697

Transactions

2

Size

1.05 KB

Version

2

Bits

0ac4c959

Nonce

1,183,829,882

Timestamp

2/15/2016, 10:04:05 PM

Confirmations

5,384,661

Merkle Root

0957e45abdb30ba188ef66fd77b2538c5f25281836b4128f7f98da788fe222b6
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.

1.580 × 10⁹⁴(95-digit number)
15803147967760014454…79761911169855659841
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
1.580 × 10⁹⁴(95-digit number)
15803147967760014454…79761911169855659841
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
3.160 × 10⁹⁴(95-digit number)
31606295935520028909…59523822339711319681
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
6.321 × 10⁹⁴(95-digit number)
63212591871040057819…19047644679422639361
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
1.264 × 10⁹⁵(96-digit number)
12642518374208011563…38095289358845278721
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
2.528 × 10⁹⁵(96-digit number)
25285036748416023127…76190578717690557441
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
5.057 × 10⁹⁵(96-digit number)
50570073496832046255…52381157435381114881
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
1.011 × 10⁹⁶(97-digit number)
10114014699366409251…04762314870762229761
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
2.022 × 10⁹⁶(97-digit number)
20228029398732818502…09524629741524459521
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
4.045 × 10⁹⁶(97-digit number)
40456058797465637004…19049259483048919041
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
8.091 × 10⁹⁶(97-digit number)
80912117594931274008…38098518966097838081
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
11
2^10 × origin + 1
1.618 × 10⁹⁷(98-digit number)
16182423518986254801…76197037932195676161
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:57,992,008 XPM·at block #6,843,454 · 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