Block #3,003,745

1CCLength 11★★★☆☆

Cunningham Chain of the First Kind · Discovered 1/10/2019, 3:47:49 PM · Difficulty 11.2074 · 3,838,663 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
9c9d395f4281e8ca2d311fc258669dd887efe36ab45bd5e70ca0c69a00d8e7ec

Height

#3,003,745

Difficulty

11.207383

Transactions

6

Size

2.46 KB

Version

2

Bits

0b35170a

Nonce

588,521,849

Timestamp

1/10/2019, 3:47:49 PM

Confirmations

3,838,663

Merkle Root

a5dade98d723914eb400a752dff252cb3d0d5b20da48a06b653ee6c83e7bff4e
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.

7.674 × 10⁹⁴(95-digit number)
76743910333444354276…96444747616842255359
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
7.674 × 10⁹⁴(95-digit number)
76743910333444354276…96444747616842255359
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
1.534 × 10⁹⁵(96-digit number)
15348782066688870855…92889495233684510719
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
3.069 × 10⁹⁵(96-digit number)
30697564133377741710…85778990467369021439
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
6.139 × 10⁹⁵(96-digit number)
61395128266755483421…71557980934738042879
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
1.227 × 10⁹⁶(97-digit number)
12279025653351096684…43115961869476085759
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
2.455 × 10⁹⁶(97-digit number)
24558051306702193368…86231923738952171519
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
4.911 × 10⁹⁶(97-digit number)
49116102613404386737…72463847477904343039
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
9.823 × 10⁹⁶(97-digit number)
98232205226808773474…44927694955808686079
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
1.964 × 10⁹⁷(98-digit number)
19646441045361754694…89855389911617372159
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
3.929 × 10⁹⁷(98-digit number)
39292882090723509389…79710779823234744319
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
11
2^10 × origin − 1
7.858 × 10⁹⁷(98-digit number)
78585764181447018779…59421559646469488639
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:57,983,677 XPM·at block #6,842,407 · updates every 60s
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