Block #548,790

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 5/17/2014, 4:56:09 AM · Difficulty 10.9598 · 6,245,397 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
45010b88169208316b173f8d0764127457e06f2e763a89d1a8fb7228ddb93aea

Height

#548,790

Difficulty

10.959809

Transactions

8

Size

4.49 KB

Version

2

Bits

0af5b60b

Nonce

1,637,190,280

Timestamp

5/17/2014, 4:56:09 AM

Confirmations

6,245,397

Merkle Root

401f1e6b135720b7e33e8aa94b671528d1bb8fc0ce0e8b496697fb135a18bafb
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.

4.657 × 10⁹⁸(99-digit number)
46577613823240237704…76400507604492309441
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
4.657 × 10⁹⁸(99-digit number)
46577613823240237704…76400507604492309441
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
9.315 × 10⁹⁸(99-digit number)
93155227646480475409…52801015208984618881
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
1.863 × 10⁹⁹(100-digit number)
18631045529296095081…05602030417969237761
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
3.726 × 10⁹⁹(100-digit number)
37262091058592190163…11204060835938475521
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
7.452 × 10⁹⁹(100-digit number)
74524182117184380327…22408121671876951041
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
1.490 × 10¹⁰⁰(101-digit number)
14904836423436876065…44816243343753902081
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
2.980 × 10¹⁰⁰(101-digit number)
29809672846873752131…89632486687507804161
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
5.961 × 10¹⁰⁰(101-digit number)
59619345693747504262…79264973375015608321
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
1.192 × 10¹⁰¹(102-digit number)
11923869138749500852…58529946750031216641
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
2.384 × 10¹⁰¹(102-digit number)
23847738277499001704…17059893500062433281
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:57,597,518 XPM·at block #6,794,186 · updates every 60s
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