Block #314,340

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 12/15/2013, 10:07:31 PM · Difficulty 10.0574 · 6,489,702 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
f99710e692644dd8ff8735a1946df7a0499006018af0589a1b26f8ec661578ab

Height

#314,340

Difficulty

10.057449

Transactions

5

Size

1.81 KB

Version

2

Bits

0a0eb4f4

Nonce

56,567

Timestamp

12/15/2013, 10:07:31 PM

Confirmations

6,489,702

Merkle Root

4fa4826f5aa8e08d8db7eed2c8d72cccc06d77aaf15697152efdbb1585309201
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.

1.962 × 10¹⁰³(104-digit number)
19620571787148495455…67456316370594867201
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
1.962 × 10¹⁰³(104-digit number)
19620571787148495455…67456316370594867201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
3.924 × 10¹⁰³(104-digit number)
39241143574296990911…34912632741189734401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
7.848 × 10¹⁰³(104-digit number)
78482287148593981822…69825265482379468801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
1.569 × 10¹⁰⁴(105-digit number)
15696457429718796364…39650530964758937601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
3.139 × 10¹⁰⁴(105-digit number)
31392914859437592728…79301061929517875201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
6.278 × 10¹⁰⁴(105-digit number)
62785829718875185457…58602123859035750401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
1.255 × 10¹⁰⁵(106-digit number)
12557165943775037091…17204247718071500801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
2.511 × 10¹⁰⁵(106-digit number)
25114331887550074183…34408495436143001601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
5.022 × 10¹⁰⁵(106-digit number)
50228663775100148366…68816990872286003201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
1.004 × 10¹⁰⁶(107-digit number)
10045732755020029673…37633981744572006401
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:57,676,389 XPM·at block #6,804,041 · updates every 60s
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