Block #472,516

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 4/3/2014, 8:10:38 AM · Difficulty 10.4353 · 6,323,378 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
47db23e96c708ce52c1290d9c67e7196a892b59c212ccf25147ff8e1d60ae5df

Height

#472,516

Difficulty

10.435283

Transactions

17

Size

52.83 KB

Version

2

Bits

0a6f6eb9

Nonce

621

Timestamp

4/3/2014, 8:10:38 AM

Confirmations

6,323,378

Merkle Root

188bade94a002ac88dedbfbd09994744075a30cef698a094384e964b053bed5c
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.

8.904 × 10¹⁰⁰(101-digit number)
89046300377041084945…47426370893467932159
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
8.904 × 10¹⁰⁰(101-digit number)
89046300377041084945…47426370893467932159
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
1.780 × 10¹⁰¹(102-digit number)
17809260075408216989…94852741786935864319
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
3.561 × 10¹⁰¹(102-digit number)
35618520150816433978…89705483573871728639
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
7.123 × 10¹⁰¹(102-digit number)
71237040301632867956…79410967147743457279
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
1.424 × 10¹⁰²(103-digit number)
14247408060326573591…58821934295486914559
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
2.849 × 10¹⁰²(103-digit number)
28494816120653147182…17643868590973829119
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
5.698 × 10¹⁰²(103-digit number)
56989632241306294365…35287737181947658239
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
1.139 × 10¹⁰³(104-digit number)
11397926448261258873…70575474363895316479
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
2.279 × 10¹⁰³(104-digit number)
22795852896522517746…41150948727790632959
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
4.559 × 10¹⁰³(104-digit number)
45591705793045035492…82301897455581265919
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:57,611,235 XPM·at block #6,795,893 · updates every 60s
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