Block #339,493

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 1/2/2014, 3:52:43 AM · Difficulty 10.1258 · 6,460,814 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
9c4550b7a5248145a94bb9a4d974400ed2f1dc39643e9b5edab507e37e7bffbc

Height

#339,493

Difficulty

10.125807

Transactions

7

Size

3.11 KB

Version

2

Bits

0a2034e1

Nonce

156,070

Timestamp

1/2/2014, 3:52:43 AM

Confirmations

6,460,814

Merkle Root

b600ccca1497846e8de395ac821a1ff645c887f7660f4ceb2d89c55fe1ae7252
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.

5.811 × 10⁹⁵(96-digit number)
58118832307247462339…32530241581238327999
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
5.811 × 10⁹⁵(96-digit number)
58118832307247462339…32530241581238327999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
1.162 × 10⁹⁶(97-digit number)
11623766461449492467…65060483162476655999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
2.324 × 10⁹⁶(97-digit number)
23247532922898984935…30120966324953311999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
4.649 × 10⁹⁶(97-digit number)
46495065845797969871…60241932649906623999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
9.299 × 10⁹⁶(97-digit number)
92990131691595939743…20483865299813247999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
1.859 × 10⁹⁷(98-digit number)
18598026338319187948…40967730599626495999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
3.719 × 10⁹⁷(98-digit number)
37196052676638375897…81935461199252991999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
7.439 × 10⁹⁷(98-digit number)
74392105353276751794…63870922398505983999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
1.487 × 10⁹⁸(99-digit number)
14878421070655350358…27741844797011967999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
2.975 × 10⁹⁸(99-digit number)
29756842141310700717…55483689594023935999
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:57,646,519 XPM·at block #6,800,306 · updates every 60s
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