Block #423,029

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 2/28/2014, 4:59:37 AM · Difficulty 10.3679 · 6,383,010 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
fe399ab7ec266a80200a5837715544b87add9e8b7390bc10fae0029271cc3b2b

Height

#423,029

Difficulty

10.367918

Transactions

10

Size

3.43 KB

Version

2

Bits

0a5e2fe5

Nonce

11,543

Timestamp

2/28/2014, 4:59:37 AM

Confirmations

6,383,010

Merkle Root

bcc7863b644fcadb9b9d6ba0aacc1fb8a4ddcbfef772cf39da6956c56a097d39
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.

6.711 × 10⁹²(93-digit number)
67111588276310158583…49736980815828882599
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
6.711 × 10⁹²(93-digit number)
67111588276310158583…49736980815828882599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
1.342 × 10⁹³(94-digit number)
13422317655262031716…99473961631657765199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
2.684 × 10⁹³(94-digit number)
26844635310524063433…98947923263315530399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
5.368 × 10⁹³(94-digit number)
53689270621048126866…97895846526631060799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
1.073 × 10⁹⁴(95-digit number)
10737854124209625373…95791693053262121599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
2.147 × 10⁹⁴(95-digit number)
21475708248419250746…91583386106524243199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
4.295 × 10⁹⁴(95-digit number)
42951416496838501493…83166772213048486399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
8.590 × 10⁹⁴(95-digit number)
85902832993677002987…66333544426096972799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
1.718 × 10⁹⁵(96-digit number)
17180566598735400597…32667088852193945599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
3.436 × 10⁹⁵(96-digit number)
34361133197470801194…65334177704387891199
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:57,692,392 XPM·at block #6,806,038 · updates every 60s
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