Block #346,614

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 1/6/2014, 4:01:43 PM · Difficulty 10.2303 · 6,449,338 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
676984a3776f3bdd1060f68afdeba0dc56423d746a09ecc51c0575207436c245

Height

#346,614

Difficulty

10.230319

Transactions

5

Size

1.08 KB

Version

2

Bits

0a3af62c

Nonce

23,979

Timestamp

1/6/2014, 4:01:43 PM

Confirmations

6,449,338

Merkle Root

4bec1cc495741d239fed50506cee509ad403bc199d78eb9f4f21ae7469afe324
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.

1.361 × 10⁹⁷(98-digit number)
13619013681304942259…64840652620129072001
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
1.361 × 10⁹⁷(98-digit number)
13619013681304942259…64840652620129072001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
2.723 × 10⁹⁷(98-digit number)
27238027362609884519…29681305240258144001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
5.447 × 10⁹⁷(98-digit number)
54476054725219769039…59362610480516288001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
1.089 × 10⁹⁸(99-digit number)
10895210945043953807…18725220961032576001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
2.179 × 10⁹⁸(99-digit number)
21790421890087907615…37450441922065152001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
4.358 × 10⁹⁸(99-digit number)
43580843780175815231…74900883844130304001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
8.716 × 10⁹⁸(99-digit number)
87161687560351630463…49801767688260608001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
1.743 × 10⁹⁹(100-digit number)
17432337512070326092…99603535376521216001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
3.486 × 10⁹⁹(100-digit number)
34864675024140652185…99207070753042432001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
6.972 × 10⁹⁹(100-digit number)
69729350048281304371…98414141506084864001
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:57,611,705 XPM·at block #6,795,951 · updates every 60s
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