Block #3,013,479

2CCLength 11★★★☆☆

Cunningham Chain of the Second Kind · Discovered 1/17/2019, 1:09:06 PM · Difficulty 11.1778 · 3,830,255 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
478945ba5bb1ba37739437a13e95d161c2b5f0ca5e2a3393c98ad379b184228d

Height

#3,013,479

Difficulty

11.177788

Transactions

5

Size

2.09 KB

Version

2

Bits

0b2d838c

Nonce

579,134,998

Timestamp

1/17/2019, 1:09:06 PM

Confirmations

3,830,255

Merkle Root

c57cb526e57d97181d57f4e7b0442a4718409fb3bc2844f749dd4be59080aecd
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.

4.587 × 10⁹⁶(97-digit number)
45872730031599458985…22926646667510333441
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
4.587 × 10⁹⁶(97-digit number)
45872730031599458985…22926646667510333441
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
9.174 × 10⁹⁶(97-digit number)
91745460063198917971…45853293335020666881
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
1.834 × 10⁹⁷(98-digit number)
18349092012639783594…91706586670041333761
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
3.669 × 10⁹⁷(98-digit number)
36698184025279567188…83413173340082667521
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
7.339 × 10⁹⁷(98-digit number)
73396368050559134376…66826346680165335041
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
1.467 × 10⁹⁸(99-digit number)
14679273610111826875…33652693360330670081
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
2.935 × 10⁹⁸(99-digit number)
29358547220223653750…67305386720661340161
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
5.871 × 10⁹⁸(99-digit number)
58717094440447307501…34610773441322680321
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
1.174 × 10⁹⁹(100-digit number)
11743418888089461500…69221546882645360641
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
2.348 × 10⁹⁹(100-digit number)
23486837776178923000…38443093765290721281
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
11
2^10 × origin + 1
4.697 × 10⁹⁹(100-digit number)
46973675552357846001…76886187530581442561
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:57,994,239 XPM·at block #6,843,733 · updates every 60s
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