Block #332,019

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 12/27/2013, 6:06:49 PM · Difficulty 10.1650 · 6,463,902 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
6b8c5a8b1389f567cd73c9f79892531ba9e031eb0c399a1e71a7461a5c01221a

Height

#332,019

Difficulty

10.164972

Transactions

11

Size

3.33 KB

Version

2

Bits

0a2a3b9c

Nonce

61,951

Timestamp

12/27/2013, 6:06:49 PM

Confirmations

6,463,902

Merkle Root

f41f2c9aa81185df73e41be16b1ed85538e9c791b852496a90dabb44d59fd392
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.

9.130 × 10⁹⁵(96-digit number)
91301280519879203125…59455145157544089601
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
9.130 × 10⁹⁵(96-digit number)
91301280519879203125…59455145157544089601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
1.826 × 10⁹⁶(97-digit number)
18260256103975840625…18910290315088179201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
3.652 × 10⁹⁶(97-digit number)
36520512207951681250…37820580630176358401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
7.304 × 10⁹⁶(97-digit number)
73041024415903362500…75641161260352716801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
1.460 × 10⁹⁷(98-digit number)
14608204883180672500…51282322520705433601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
2.921 × 10⁹⁷(98-digit number)
29216409766361345000…02564645041410867201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
5.843 × 10⁹⁷(98-digit number)
58432819532722690000…05129290082821734401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
1.168 × 10⁹⁸(99-digit number)
11686563906544538000…10258580165643468801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
2.337 × 10⁹⁸(99-digit number)
23373127813089076000…20517160331286937601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
4.674 × 10⁹⁸(99-digit number)
46746255626178152000…41034320662573875201
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:57,611,455 XPM·at block #6,795,920 · updates every 60s
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