Block #330,722

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 12/26/2013, 9:12:38 PM · Difficulty 10.1676 · 6,475,183 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
66ce268c9d564b713cef3365261bc05fec44f365ffb5cdbdd8af5cc31800f170

Height

#330,722

Difficulty

10.167605

Transactions

2

Size

1.10 KB

Version

2

Bits

0a2ae82c

Nonce

1,046,426

Timestamp

12/26/2013, 9:12:38 PM

Confirmations

6,475,183

Merkle Root

d98d8ba4046c96d267957eb603d29e857aec3460bd7c6c71ef027e58bcf63b9a
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.

9.883 × 10¹⁰¹(102-digit number)
98831651511539919049…67841012356537520639
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
9.883 × 10¹⁰¹(102-digit number)
98831651511539919049…67841012356537520639
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
1.976 × 10¹⁰²(103-digit number)
19766330302307983809…35682024713075041279
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
3.953 × 10¹⁰²(103-digit number)
39532660604615967619…71364049426150082559
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
7.906 × 10¹⁰²(103-digit number)
79065321209231935239…42728098852300165119
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
1.581 × 10¹⁰³(104-digit number)
15813064241846387047…85456197704600330239
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
3.162 × 10¹⁰³(104-digit number)
31626128483692774095…70912395409200660479
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
6.325 × 10¹⁰³(104-digit number)
63252256967385548191…41824790818401320959
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
1.265 × 10¹⁰⁴(105-digit number)
12650451393477109638…83649581636802641919
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
2.530 × 10¹⁰⁴(105-digit number)
25300902786954219276…67299163273605283839
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
5.060 × 10¹⁰⁴(105-digit number)
50601805573908438553…34598326547210567679
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:57,691,329 XPM·at block #6,805,904 · updates every 60s
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