Block #471,161

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 4/2/2014, 10:04:30 AM · Difficulty 10.4314 · 6,323,129 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
0786f143dbfe13bf7307c47aeb29fffa19f68d0137ba1fe02bc7fafd416db16e

Height

#471,161

Difficulty

10.431363

Transactions

3

Size

1.43 KB

Version

2

Bits

0a6e6dd0

Nonce

119,644

Timestamp

4/2/2014, 10:04:30 AM

Confirmations

6,323,129

Merkle Root

31a5e9b22069ed04ce6b8de0951dbe1fbf4266ce6855713f5fdd172da4547ba9
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.

2.237 × 10⁹⁹(100-digit number)
22375536772624412416…72522861727409290239
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
2.237 × 10⁹⁹(100-digit number)
22375536772624412416…72522861727409290239
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
4.475 × 10⁹⁹(100-digit number)
44751073545248824832…45045723454818580479
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
8.950 × 10⁹⁹(100-digit number)
89502147090497649665…90091446909637160959
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
1.790 × 10¹⁰⁰(101-digit number)
17900429418099529933…80182893819274321919
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
3.580 × 10¹⁰⁰(101-digit number)
35800858836199059866…60365787638548643839
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
7.160 × 10¹⁰⁰(101-digit number)
71601717672398119732…20731575277097287679
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
1.432 × 10¹⁰¹(102-digit number)
14320343534479623946…41463150554194575359
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
2.864 × 10¹⁰¹(102-digit number)
28640687068959247892…82926301108389150719
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
5.728 × 10¹⁰¹(102-digit number)
57281374137918495785…65852602216778301439
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
1.145 × 10¹⁰²(103-digit number)
11456274827583699157…31705204433556602879
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:57,598,351 XPM·at block #6,794,289 · updates every 60s
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