Block #3,502,025

1CCLength 11★★★☆☆

Cunningham Chain of the First Kind · Discovered 1/6/2020, 5:54:02 AM · Difficulty 10.9307 · 3,340,234 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
3d71385c0ca99bd03bc8d5d3452d46bb90b7f34a5bd3200ef44a69cbf12d4858

Height

#3,502,025

Difficulty

10.930721

Transactions

5

Size

4.70 KB

Version

2

Bits

0aee43b7

Nonce

636,806,348

Timestamp

1/6/2020, 5:54:02 AM

Confirmations

3,340,234

Merkle Root

652a7da238596a3341327888f485b666a9774ccecde07275b58e7fafa3ba0183
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.

9.663 × 10⁹⁵(96-digit number)
96633028527439915999…36466513449815295999
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
9.663 × 10⁹⁵(96-digit number)
96633028527439915999…36466513449815295999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
1.932 × 10⁹⁶(97-digit number)
19326605705487983199…72933026899630591999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
3.865 × 10⁹⁶(97-digit number)
38653211410975966399…45866053799261183999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
7.730 × 10⁹⁶(97-digit number)
77306422821951932799…91732107598522367999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
1.546 × 10⁹⁷(98-digit number)
15461284564390386559…83464215197044735999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
3.092 × 10⁹⁷(98-digit number)
30922569128780773119…66928430394089471999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
6.184 × 10⁹⁷(98-digit number)
61845138257561546239…33856860788178943999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
1.236 × 10⁹⁸(99-digit number)
12369027651512309247…67713721576357887999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
2.473 × 10⁹⁸(99-digit number)
24738055303024618495…35427443152715775999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
4.947 × 10⁹⁸(99-digit number)
49476110606049236991…70854886305431551999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
11
2^10 × origin − 1
9.895 × 10⁹⁸(99-digit number)
98952221212098473983…41709772610863103999
Verify on FactorDB ↗Wolfram Alpha ↗

What this block proved

The miner who found this block proved the existence of 11 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
RareChain length 11

Approximately 1 in 1,000 blocks. Noteworthy discoveries.

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:57,982,470 XPM·at block #6,842,258 · updates every 60s
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