Block #450,140

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 3/19/2014, 2:30:22 AM · Difficulty 10.3698 · 6,346,053 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
101a1d8d57501fbca383cd064367a3a0d4d0ecbcc6b7a009bec7e6fa11a46126

Height

#450,140

Difficulty

10.369825

Transactions

3

Size

5.04 KB

Version

2

Bits

0a5eacd7

Nonce

99,827

Timestamp

3/19/2014, 2:30:22 AM

Confirmations

6,346,053

Merkle Root

51dbd67b255a2bc3af00721ddf7a6696a354d953558c077f5ac1d26c817826c7
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.

1.847 × 10⁹⁵(96-digit number)
18478259498460292428…67454378598321066699
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
1.847 × 10⁹⁵(96-digit number)
18478259498460292428…67454378598321066699
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
3.695 × 10⁹⁵(96-digit number)
36956518996920584856…34908757196642133399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
7.391 × 10⁹⁵(96-digit number)
73913037993841169712…69817514393284266799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
1.478 × 10⁹⁶(97-digit number)
14782607598768233942…39635028786568533599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
2.956 × 10⁹⁶(97-digit number)
29565215197536467884…79270057573137067199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
5.913 × 10⁹⁶(97-digit number)
59130430395072935769…58540115146274134399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
1.182 × 10⁹⁷(98-digit number)
11826086079014587153…17080230292548268799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
2.365 × 10⁹⁷(98-digit number)
23652172158029174307…34160460585096537599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
4.730 × 10⁹⁷(98-digit number)
47304344316058348615…68320921170193075199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
9.460 × 10⁹⁷(98-digit number)
94608688632116697231…36641842340386150399
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:57,613,544 XPM·at block #6,796,192 · updates every 60s
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