Block #337,377

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 12/31/2013, 3:29:43 PM · Difficulty 10.1363 · 6,459,134 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
040e4d498d2d52fde0939166be6eedf2ac9f902106ae97923ff47cbde4554939

Height

#337,377

Difficulty

10.136283

Transactions

5

Size

1.62 KB

Version

2

Bits

0a22e378

Nonce

401,597

Timestamp

12/31/2013, 3:29:43 PM

Confirmations

6,459,134

Merkle Root

4c797c727456f1e6a8acd92f23bc88d8ab2df20e47540584c695b69ed92c2e21
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.

4.691 × 10⁹⁸(99-digit number)
46919702075845199838…96471153090668310241
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
4.691 × 10⁹⁸(99-digit number)
46919702075845199838…96471153090668310241
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
9.383 × 10⁹⁸(99-digit number)
93839404151690399677…92942306181336620481
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
1.876 × 10⁹⁹(100-digit number)
18767880830338079935…85884612362673240961
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
3.753 × 10⁹⁹(100-digit number)
37535761660676159871…71769224725346481921
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
7.507 × 10⁹⁹(100-digit number)
75071523321352319742…43538449450692963841
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
1.501 × 10¹⁰⁰(101-digit number)
15014304664270463948…87076898901385927681
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
3.002 × 10¹⁰⁰(101-digit number)
30028609328540927896…74153797802771855361
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
6.005 × 10¹⁰⁰(101-digit number)
60057218657081855793…48307595605543710721
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
1.201 × 10¹⁰¹(102-digit number)
12011443731416371158…96615191211087421441
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
2.402 × 10¹⁰¹(102-digit number)
24022887462832742317…93230382422174842881
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:57,616,091 XPM·at block #6,796,510 · updates every 60s
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