Block #314,530

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 12/16/2013, 12:33:36 AM · Difficulty 10.0659 · 6,491,368 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
449fb307faf47c1fbbcc71495c40742cb1e7e9b4bb616e4a756cc9eca95033ec

Height

#314,530

Difficulty

10.065932

Transactions

17

Size

6.52 KB

Version

2

Bits

0a10e0e9

Nonce

19,874

Timestamp

12/16/2013, 12:33:36 AM

Confirmations

6,491,368

Merkle Root

88a140e4f0249dc37f6f8a02841dabdf8e808d3a5b5c99c3782d3dc52cde8c1f
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.

5.814 × 10¹⁰⁰(101-digit number)
58143050079678390733…96544537246327919521
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
5.814 × 10¹⁰⁰(101-digit number)
58143050079678390733…96544537246327919521
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
1.162 × 10¹⁰¹(102-digit number)
11628610015935678146…93089074492655839041
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
2.325 × 10¹⁰¹(102-digit number)
23257220031871356293…86178148985311678081
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
4.651 × 10¹⁰¹(102-digit number)
46514440063742712586…72356297970623356161
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
9.302 × 10¹⁰¹(102-digit number)
93028880127485425172…44712595941246712321
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
1.860 × 10¹⁰²(103-digit number)
18605776025497085034…89425191882493424641
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
3.721 × 10¹⁰²(103-digit number)
37211552050994170069…78850383764986849281
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
7.442 × 10¹⁰²(103-digit number)
74423104101988340138…57700767529973698561
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
1.488 × 10¹⁰³(104-digit number)
14884620820397668027…15401535059947397121
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
2.976 × 10¹⁰³(104-digit number)
29769241640795336055…30803070119894794241
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:57,691,271 XPM·at block #6,805,897 · updates every 60s
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