Block #1,112,445

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 6/17/2015, 7:31:05 AM · Difficulty 10.8957 · 5,686,554 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
e917854021bcf2b313b863020b81911e123b5fa244434e7eaa7bea23fe68229c

Height

#1,112,445

Difficulty

10.895677

Transactions

3

Size

20.00 KB

Version

2

Bits

0ae54b1d

Nonce

740,180,286

Timestamp

6/17/2015, 7:31:05 AM

Confirmations

5,686,554

Merkle Root

e3dc59b2d4df0cfaf25a4327bfb170cdafabbe0b809768c5a51f138ec69ccaf3
Transactions (3)
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.

5.300 × 10⁹⁴(95-digit number)
53005322866844848910…89271701152363301119
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
5.300 × 10⁹⁴(95-digit number)
53005322866844848910…89271701152363301119
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
1.060 × 10⁹⁵(96-digit number)
10601064573368969782…78543402304726602239
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
2.120 × 10⁹⁵(96-digit number)
21202129146737939564…57086804609453204479
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
4.240 × 10⁹⁵(96-digit number)
42404258293475879128…14173609218906408959
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
8.480 × 10⁹⁵(96-digit number)
84808516586951758256…28347218437812817919
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
1.696 × 10⁹⁶(97-digit number)
16961703317390351651…56694436875625635839
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
3.392 × 10⁹⁶(97-digit number)
33923406634780703302…13388873751251271679
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
6.784 × 10⁹⁶(97-digit number)
67846813269561406605…26777747502502543359
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
1.356 × 10⁹⁷(98-digit number)
13569362653912281321…53555495005005086719
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
2.713 × 10⁹⁷(98-digit number)
27138725307824562642…07110990010010173439
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:57,636,032 XPM·at block #6,798,998 · updates every 60s
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