Block #383,449

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 1/31/2014, 10:30:06 AM · Difficulty 10.4005 · 6,412,693 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
dcce3f3cab38d7b09e83a82e46b708171d5b924f69dc8b5258e4e82fabce566f

Height

#383,449

Difficulty

10.400549

Transactions

2

Size

845 B

Version

2

Bits

0a668a64

Nonce

8,646

Timestamp

1/31/2014, 10:30:06 AM

Confirmations

6,412,693

Merkle Root

dbf4e45a2566c233daa11af178d202e6742b02e4c262683e056641cbac048a43
Transactions (2)
1 in → 1 out9.2400 XPM116 B
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.

1.878 × 10¹⁰⁰(101-digit number)
18780629627803099252…27072914569109626879
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
1.878 × 10¹⁰⁰(101-digit number)
18780629627803099252…27072914569109626879
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
3.756 × 10¹⁰⁰(101-digit number)
37561259255606198504…54145829138219253759
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
7.512 × 10¹⁰⁰(101-digit number)
75122518511212397008…08291658276438507519
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
1.502 × 10¹⁰¹(102-digit number)
15024503702242479401…16583316552877015039
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
3.004 × 10¹⁰¹(102-digit number)
30049007404484958803…33166633105754030079
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
6.009 × 10¹⁰¹(102-digit number)
60098014808969917607…66333266211508060159
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
1.201 × 10¹⁰²(103-digit number)
12019602961793983521…32666532423016120319
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
2.403 × 10¹⁰²(103-digit number)
24039205923587967042…65333064846032240639
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
4.807 × 10¹⁰²(103-digit number)
48078411847175934085…30666129692064481279
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
9.615 × 10¹⁰²(103-digit number)
96156823694351868171…61332259384128962559
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:57,613,133 XPM·at block #6,796,141 · updates every 60s
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