Block #541,146

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 5/13/2014, 9:46:51 AM · Difficulty 10.9378 · 6,261,415 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
6dc78602177ea87736289cd7672690febfaeeaf2111e02fc27ccd1061b9abb2a

Height

#541,146

Difficulty

10.937802

Transactions

6

Size

1.45 KB

Version

2

Bits

0af013c8

Nonce

68,225,033

Timestamp

5/13/2014, 9:46:51 AM

Confirmations

6,261,415

Merkle Root

9d34dfbbb4b1e8c27a476564d5919c9643e65f561b7d00771c1b1a67113adb4c
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.

2.590 × 10⁹⁸(99-digit number)
25906790577249931936…50316299338812187601
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
2.590 × 10⁹⁸(99-digit number)
25906790577249931936…50316299338812187601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
5.181 × 10⁹⁸(99-digit number)
51813581154499863873…00632598677624375201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
1.036 × 10⁹⁹(100-digit number)
10362716230899972774…01265197355248750401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
2.072 × 10⁹⁹(100-digit number)
20725432461799945549…02530394710497500801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
4.145 × 10⁹⁹(100-digit number)
41450864923599891098…05060789420995001601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
8.290 × 10⁹⁹(100-digit number)
82901729847199782197…10121578841990003201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
1.658 × 10¹⁰⁰(101-digit number)
16580345969439956439…20243157683980006401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
3.316 × 10¹⁰⁰(101-digit number)
33160691938879912879…40486315367960012801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
6.632 × 10¹⁰⁰(101-digit number)
66321383877759825758…80972630735920025601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
1.326 × 10¹⁰¹(102-digit number)
13264276775551965151…61945261471840051201
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:57,664,502 XPM·at block #6,802,560 · updates every 60s
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