Block #332,875

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 12/28/2013, 9:26:26 AM · Difficulty 10.1652 · 6,469,771 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
e30d41fc1d18a17cb60bc512a565b84e2434072bbaad97fe7cd91737d4455ce4

Height

#332,875

Difficulty

10.165243

Transactions

9

Size

16.61 KB

Version

2

Bits

0a2a4d5b

Nonce

59,343

Timestamp

12/28/2013, 9:26:26 AM

Confirmations

6,469,771

Merkle Root

8db8b244c7a5e5db0fae75e33ab10590e5dd666d2f51ab97a37a63e45886d741
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.

7.997 × 10¹⁰¹(102-digit number)
79976414663644191946…39730326987386667521
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
7.997 × 10¹⁰¹(102-digit number)
79976414663644191946…39730326987386667521
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
1.599 × 10¹⁰²(103-digit number)
15995282932728838389…79460653974773335041
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
3.199 × 10¹⁰²(103-digit number)
31990565865457676778…58921307949546670081
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
6.398 × 10¹⁰²(103-digit number)
63981131730915353557…17842615899093340161
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
1.279 × 10¹⁰³(104-digit number)
12796226346183070711…35685231798186680321
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
2.559 × 10¹⁰³(104-digit number)
25592452692366141423…71370463596373360641
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
5.118 × 10¹⁰³(104-digit number)
51184905384732282846…42740927192746721281
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
1.023 × 10¹⁰⁴(105-digit number)
10236981076946456569…85481854385493442561
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
2.047 × 10¹⁰⁴(105-digit number)
20473962153892913138…70963708770986885121
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
4.094 × 10¹⁰⁴(105-digit number)
40947924307785826276…41927417541973770241
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:57,665,184 XPM·at block #6,802,645 · updates every 60s
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