Block #554,339

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 5/20/2014, 7:17:53 PM · Difficulty 10.9628 · 6,261,915 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
41e1a9f60a9f437f95eb433cbffdec2f808d7062cf66ecdf9890ae8b9ecf9030

Height

#554,339

Difficulty

10.962813

Transactions

9

Size

2.69 KB

Version

2

Bits

0af67aef

Nonce

184,744,085

Timestamp

5/20/2014, 7:17:53 PM

Confirmations

6,261,915

Merkle Root

90fc83af33045ac5db8e58255e088504e4401b6d7ff6d36eefe6d2c758e3a890
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.

2.732 × 10⁹⁸(99-digit number)
27326675322416884542…71081918443118145199
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
2.732 × 10⁹⁸(99-digit number)
27326675322416884542…71081918443118145199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
5.465 × 10⁹⁸(99-digit number)
54653350644833769085…42163836886236290399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
1.093 × 10⁹⁹(100-digit number)
10930670128966753817…84327673772472580799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
2.186 × 10⁹⁹(100-digit number)
21861340257933507634…68655347544945161599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
4.372 × 10⁹⁹(100-digit number)
43722680515867015268…37310695089890323199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
8.744 × 10⁹⁹(100-digit number)
87445361031734030536…74621390179780646399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
1.748 × 10¹⁰⁰(101-digit number)
17489072206346806107…49242780359561292799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
3.497 × 10¹⁰⁰(101-digit number)
34978144412693612214…98485560719122585599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
6.995 × 10¹⁰⁰(101-digit number)
69956288825387224429…96971121438245171199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
1.399 × 10¹⁰¹(102-digit number)
13991257765077444885…93942242876490342399
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:57,774,152 XPM·at block #6,816,253 · updates every 60s
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