Block #412,002

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 2/20/2014, 5:46:35 AM · Difficulty 10.4162 · 6,414,571 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
d62677372ba7ed3fcbe4447641010effab335b4f078039097f84f372b9bcc004

Height

#412,002

Difficulty

10.416246

Transactions

8

Size

3.44 KB

Version

2

Bits

0a6a8f20

Nonce

451,025

Timestamp

2/20/2014, 5:46:35 AM

Confirmations

6,414,571

Merkle Root

05b486a3acacd6f1a3ea199b0932dbcb3abfdb380c9cd3661bf42bdb8de1f8e3
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.

1.498 × 10⁹⁵(96-digit number)
14988997675309990701…10065072526542264001
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
1.498 × 10⁹⁵(96-digit number)
14988997675309990701…10065072526542264001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
2.997 × 10⁹⁵(96-digit number)
29977995350619981403…20130145053084528001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
5.995 × 10⁹⁵(96-digit number)
59955990701239962807…40260290106169056001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
1.199 × 10⁹⁶(97-digit number)
11991198140247992561…80520580212338112001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
2.398 × 10⁹⁶(97-digit number)
23982396280495985123…61041160424676224001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
4.796 × 10⁹⁶(97-digit number)
47964792560991970246…22082320849352448001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
9.592 × 10⁹⁶(97-digit number)
95929585121983940492…44164641698704896001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
1.918 × 10⁹⁷(98-digit number)
19185917024396788098…88329283397409792001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
3.837 × 10⁹⁷(98-digit number)
38371834048793576196…76658566794819584001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
7.674 × 10⁹⁷(98-digit number)
76743668097587152393…53317133589639168001
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:57,856,733 XPM·at block #6,826,572 · updates every 60s
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