Block #482,817

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 4/9/2014, 5:25:04 PM · Difficulty 10.5508 · 6,325,491 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
7d9ba496044db7f8345e0ce6355766dafb5076fb0cd330faf9769c66d0cb9764

Height

#482,817

Difficulty

10.550774

Transactions

9

Size

1.96 KB

Version

2

Bits

0a8cff8c

Nonce

15,874,432

Timestamp

4/9/2014, 5:25:04 PM

Confirmations

6,325,491

Merkle Root

e763d09e198af8db14a549b0bfb414f6e952c0b23330ac5730f16a411bae1377
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.

6.893 × 10⁹⁹(100-digit number)
68931920326190505576…98477869979391759361
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
6.893 × 10⁹⁹(100-digit number)
68931920326190505576…98477869979391759361
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
1.378 × 10¹⁰⁰(101-digit number)
13786384065238101115…96955739958783518721
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
2.757 × 10¹⁰⁰(101-digit number)
27572768130476202230…93911479917567037441
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
5.514 × 10¹⁰⁰(101-digit number)
55145536260952404460…87822959835134074881
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
1.102 × 10¹⁰¹(102-digit number)
11029107252190480892…75645919670268149761
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
2.205 × 10¹⁰¹(102-digit number)
22058214504380961784…51291839340536299521
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
4.411 × 10¹⁰¹(102-digit number)
44116429008761923568…02583678681072599041
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
8.823 × 10¹⁰¹(102-digit number)
88232858017523847137…05167357362145198081
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
1.764 × 10¹⁰²(103-digit number)
17646571603504769427…10334714724290396161
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
3.529 × 10¹⁰²(103-digit number)
35293143207009538854…20669429448580792321
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:57,710,519 XPM·at block #6,808,307 · updates every 60s
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