Block #332,491

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 12/28/2013, 2:39:33 AM · Difficulty 10.1708 · 6,460,343 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
95905a790f416b4110b94741b975d94b96d00ffa34b92a55e2edf6475536e70d

Height

#332,491

Difficulty

10.170839

Transactions

11

Size

3.23 KB

Version

2

Bits

0a2bbc21

Nonce

241,031

Timestamp

12/28/2013, 2:39:33 AM

Confirmations

6,460,343

Merkle Root

1e98ae882b56a0ea9d226c9f267b5501e0f187049653d3e62cca96007c234cee
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.

1.089 × 10⁹³(94-digit number)
10891963799800132867…81491138065348584959
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
1.089 × 10⁹³(94-digit number)
10891963799800132867…81491138065348584959
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
2.178 × 10⁹³(94-digit number)
21783927599600265734…62982276130697169919
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
4.356 × 10⁹³(94-digit number)
43567855199200531468…25964552261394339839
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
8.713 × 10⁹³(94-digit number)
87135710398401062937…51929104522788679679
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
1.742 × 10⁹⁴(95-digit number)
17427142079680212587…03858209045577359359
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
3.485 × 10⁹⁴(95-digit number)
34854284159360425175…07716418091154718719
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
6.970 × 10⁹⁴(95-digit number)
69708568318720850350…15432836182309437439
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
1.394 × 10⁹⁵(96-digit number)
13941713663744170070…30865672364618874879
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
2.788 × 10⁹⁵(96-digit number)
27883427327488340140…61731344729237749759
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
5.576 × 10⁹⁵(96-digit number)
55766854654976680280…23462689458475499519
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 First 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 1CC formula:

1CC: p₁ (first prime), p₂ = 2p₁ + 1, p₃ = 2p₂ + 1, …
Circulating Supply:57,586,653 XPM·at block #6,792,833 · updates every 60s
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