Block #334,823

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 12/29/2013, 6:35:19 PM · Difficulty 10.1590 · 6,467,972 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
e0562446e2be598b6e7f432ee79190bcaaf3ebcb121838a17c1159d17e3b5ebd

Height

#334,823

Difficulty

10.158972

Transactions

15

Size

4.79 KB

Version

2

Bits

0a28b25e

Nonce

38,658

Timestamp

12/29/2013, 6:35:19 PM

Confirmations

6,467,972

Merkle Root

2612555c9caef95bd39409a18eef08187a84266f1ea92151cc467d93624ef83b
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.

7.793 × 10¹⁰¹(102-digit number)
77936714320489941617…95597661869295393921
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
7.793 × 10¹⁰¹(102-digit number)
77936714320489941617…95597661869295393921
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
1.558 × 10¹⁰²(103-digit number)
15587342864097988323…91195323738590787841
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
3.117 × 10¹⁰²(103-digit number)
31174685728195976646…82390647477181575681
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
6.234 × 10¹⁰²(103-digit number)
62349371456391953293…64781294954363151361
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
1.246 × 10¹⁰³(104-digit number)
12469874291278390658…29562589908726302721
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
2.493 × 10¹⁰³(104-digit number)
24939748582556781317…59125179817452605441
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
4.987 × 10¹⁰³(104-digit number)
49879497165113562634…18250359634905210881
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
9.975 × 10¹⁰³(104-digit number)
99758994330227125269…36500719269810421761
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
1.995 × 10¹⁰⁴(105-digit number)
19951798866045425053…73001438539620843521
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
3.990 × 10¹⁰⁴(105-digit number)
39903597732090850107…46002877079241687041
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:57,666,387 XPM·at block #6,802,794 · updates every 60s
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