Block #432,983

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 3/7/2014, 7:15:38 AM · Difficulty 10.3392 · 6,394,081 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
ab8fc505fb9a34423a581c920b264d5d4573a824b94488ace40a943a2d263c04

Height

#432,983

Difficulty

10.339232

Transactions

2

Size

1.94 KB

Version

2

Bits

0a56d7f0

Nonce

21,993

Timestamp

3/7/2014, 7:15:38 AM

Confirmations

6,394,081

Merkle Root

e0f8d6a9ede7f471fb4b64124be04370d2b23a9a09be66a993e30fbe9705314b
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.

7.160 × 10⁹⁵(96-digit number)
71607583557064322140…37079718018962268161
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
7.160 × 10⁹⁵(96-digit number)
71607583557064322140…37079718018962268161
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
1.432 × 10⁹⁶(97-digit number)
14321516711412864428…74159436037924536321
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
2.864 × 10⁹⁶(97-digit number)
28643033422825728856…48318872075849072641
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
5.728 × 10⁹⁶(97-digit number)
57286066845651457712…96637744151698145281
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
1.145 × 10⁹⁷(98-digit number)
11457213369130291542…93275488303396290561
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
2.291 × 10⁹⁷(98-digit number)
22914426738260583084…86550976606792581121
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
4.582 × 10⁹⁷(98-digit number)
45828853476521166169…73101953213585162241
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
9.165 × 10⁹⁷(98-digit number)
91657706953042332339…46203906427170324481
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
1.833 × 10⁹⁸(99-digit number)
18331541390608466467…92407812854340648961
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
3.666 × 10⁹⁸(99-digit number)
36663082781216932935…84815625708681297921
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:57,860,696 XPM·at block #6,827,063 · updates every 60s
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