Block #3,035,782

2CCLength 11★★★☆☆

Cunningham Chain of the Second Kind · Discovered 2/2/2019, 4:30:41 PM · Difficulty 11.0109 · 3,803,017 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
dad08e0192c98b78afce850b0a61ee5d3ef1b5943de79e738fef5919dfb3df73

Height

#3,035,782

Difficulty

11.010870

Transactions

2

Size

1.43 KB

Version

2

Bits

0b02c85a

Nonce

810,987,482

Timestamp

2/2/2019, 4:30:41 PM

Confirmations

3,803,017

Merkle Root

df9ee8ed68c7c9e506a36b605a53019b01d145e1aa43a5932f9344c8b0efeee6
Transactions (2)
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.

8.699 × 10⁹²(93-digit number)
86991297836469286858…10762961986769535041
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
8.699 × 10⁹²(93-digit number)
86991297836469286858…10762961986769535041
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
1.739 × 10⁹³(94-digit number)
17398259567293857371…21525923973539070081
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
3.479 × 10⁹³(94-digit number)
34796519134587714743…43051847947078140161
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
6.959 × 10⁹³(94-digit number)
69593038269175429486…86103695894156280321
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
1.391 × 10⁹⁴(95-digit number)
13918607653835085897…72207391788312560641
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
2.783 × 10⁹⁴(95-digit number)
27837215307670171794…44414783576625121281
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
5.567 × 10⁹⁴(95-digit number)
55674430615340343589…88829567153250242561
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
1.113 × 10⁹⁵(96-digit number)
11134886123068068717…77659134306500485121
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
2.226 × 10⁹⁵(96-digit number)
22269772246136137435…55318268613000970241
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
4.453 × 10⁹⁵(96-digit number)
44539544492272274871…10636537226001940481
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
11
2^10 × origin + 1
8.907 × 10⁹⁵(96-digit number)
89079088984544549743…21273074452003880961
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:57,954,656 XPM·at block #6,838,798 · updates every 60s
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