Block #440,155

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 3/12/2014, 5:45:00 AM · Difficulty 10.3510 · 6,370,844 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
6165d8357adf15c8f730a935ab24b3a5308006caa42691219d09657454556552

Height

#440,155

Difficulty

10.351003

Transactions

1

Size

968 B

Version

2

Bits

0a59db4d

Nonce

97,729

Timestamp

3/12/2014, 5:45:00 AM

Confirmations

6,370,844

Merkle Root

85e4ef3a7a3f18694cb4edb27aea0050f2995302faa1966006f6f7f0320b6532
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.

5.148 × 10⁹²(93-digit number)
51481636936898653972…80655146365867427679
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
5.148 × 10⁹²(93-digit number)
51481636936898653972…80655146365867427679
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
1.029 × 10⁹³(94-digit number)
10296327387379730794…61310292731734855359
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
2.059 × 10⁹³(94-digit number)
20592654774759461588…22620585463469710719
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
4.118 × 10⁹³(94-digit number)
41185309549518923177…45241170926939421439
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
8.237 × 10⁹³(94-digit number)
82370619099037846355…90482341853878842879
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
1.647 × 10⁹⁴(95-digit number)
16474123819807569271…80964683707757685759
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
3.294 × 10⁹⁴(95-digit number)
32948247639615138542…61929367415515371519
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
6.589 × 10⁹⁴(95-digit number)
65896495279230277084…23858734831030743039
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
1.317 × 10⁹⁵(96-digit number)
13179299055846055416…47717469662061486079
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
2.635 × 10⁹⁵(96-digit number)
26358598111692110833…95434939324122972159
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:57,732,095 XPM·at block #6,810,998 · updates every 60s
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