Block #492,214

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 4/14/2014, 11:30:16 PM · Difficulty 10.6888 · 6,312,949 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
b455c7c745406e124f8f13342f50fa58889fa58e640bed3338c30d1e7c7987b8

Height

#492,214

Difficulty

10.688813

Transactions

3

Size

652 B

Version

2

Bits

0ab05614

Nonce

20,129

Timestamp

4/14/2014, 11:30:16 PM

Confirmations

6,312,949

Merkle Root

4d9971607f287be3f9f70a679c55423be46d0b646a4f5df0483423da96437a3f
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.

2.173 × 10⁹⁵(96-digit number)
21736063320061042210…37537803047852817799
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
2.173 × 10⁹⁵(96-digit number)
21736063320061042210…37537803047852817799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
4.347 × 10⁹⁵(96-digit number)
43472126640122084420…75075606095705635599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
8.694 × 10⁹⁵(96-digit number)
86944253280244168841…50151212191411271199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
1.738 × 10⁹⁶(97-digit number)
17388850656048833768…00302424382822542399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
3.477 × 10⁹⁶(97-digit number)
34777701312097667536…00604848765645084799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
6.955 × 10⁹⁶(97-digit number)
69555402624195335073…01209697531290169599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
1.391 × 10⁹⁷(98-digit number)
13911080524839067014…02419395062580339199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
2.782 × 10⁹⁷(98-digit number)
27822161049678134029…04838790125160678399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
5.564 × 10⁹⁷(98-digit number)
55644322099356268058…09677580250321356799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
1.112 × 10⁹⁸(99-digit number)
11128864419871253611…19355160500642713599
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:57,685,371 XPM·at block #6,805,162 · updates every 60s
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