Block #3,051,048

1CCLength 11★★★☆☆

Cunningham Chain of the First Kind · Discovered 2/13/2019, 11:25:06 AM · Difficulty 10.9961 · 3,790,007 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
257930dd916de299229f3d4f2a4478252afcf18297c99c60fb8e28cc1d7515c4

Height

#3,051,048

Difficulty

10.996075

Transactions

7

Size

1.71 KB

Version

2

Bits

0afefec0

Nonce

260,029,300

Timestamp

2/13/2019, 11:25:06 AM

Confirmations

3,790,007

Merkle Root

42f2e17f331d8b2a54cf584a7e82c6d8e2c7e26adf6d29197e112aafe6558cb1
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.

7.893 × 10⁹³(94-digit number)
78933903185866654097…65266060017095774719
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
7.893 × 10⁹³(94-digit number)
78933903185866654097…65266060017095774719
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
1.578 × 10⁹⁴(95-digit number)
15786780637173330819…30532120034191549439
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
3.157 × 10⁹⁴(95-digit number)
31573561274346661638…61064240068383098879
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
6.314 × 10⁹⁴(95-digit number)
63147122548693323277…22128480136766197759
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
1.262 × 10⁹⁵(96-digit number)
12629424509738664655…44256960273532395519
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
2.525 × 10⁹⁵(96-digit number)
25258849019477329311…88513920547064791039
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
5.051 × 10⁹⁵(96-digit number)
50517698038954658622…77027841094129582079
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
1.010 × 10⁹⁶(97-digit number)
10103539607790931724…54055682188259164159
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
2.020 × 10⁹⁶(97-digit number)
20207079215581863448…08111364376518328319
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
4.041 × 10⁹⁶(97-digit number)
40414158431163726897…16222728753036656639
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
11
2^10 × origin − 1
8.082 × 10⁹⁶(97-digit number)
80828316862327453795…32445457506073313279
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 First 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 1CC formula:

1CC: p₁ (first prime), p₂ = 2p₁ + 1, p₃ = 2p₂ + 1, …
Circulating Supply:57,972,804 XPM·at block #6,841,054 · updates every 60s
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