Block #3,123,490

1CCLength 11★★★☆☆

Cunningham Chain of the First Kind · Discovered 4/3/2019, 5:53:50 PM · Difficulty 11.3202 · 3,717,429 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
ea6057f751e6f150e669115ae499a64ce3ab4532506f82d53f2d1107667d77e3

Height

#3,123,490

Difficulty

11.320180

Transactions

2

Size

1018 B

Version

2

Bits

0b51f749

Nonce

956,613,790

Timestamp

4/3/2019, 5:53:50 PM

Confirmations

3,717,429

Merkle Root

b0ba6475501e68f2ae98878786cf3f6fdf76bca6a63701665a0a1bc1e3e4b59c
Transactions (2)
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.

1.285 × 10⁹⁵(96-digit number)
12852595991391933824…03341513170145093119
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
1.285 × 10⁹⁵(96-digit number)
12852595991391933824…03341513170145093119
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
2.570 × 10⁹⁵(96-digit number)
25705191982783867648…06683026340290186239
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
5.141 × 10⁹⁵(96-digit number)
51410383965567735297…13366052680580372479
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
1.028 × 10⁹⁶(97-digit number)
10282076793113547059…26732105361160744959
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
2.056 × 10⁹⁶(97-digit number)
20564153586227094119…53464210722321489919
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
4.112 × 10⁹⁶(97-digit number)
41128307172454188238…06928421444642979839
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
8.225 × 10⁹⁶(97-digit number)
82256614344908376476…13856842889285959679
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
1.645 × 10⁹⁷(98-digit number)
16451322868981675295…27713685778571919359
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
3.290 × 10⁹⁷(98-digit number)
32902645737963350590…55427371557143838719
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
6.580 × 10⁹⁷(98-digit number)
65805291475926701181…10854743114287677439
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
11
2^10 × origin − 1
1.316 × 10⁹⁸(99-digit number)
13161058295185340236…21709486228575354879
Verify on FactorDB ↗Wolfram Alpha ↗

What this block proved

The miner who found this block proved the existence of 11 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
RareChain length 11

Approximately 1 in 1,000 blocks. Noteworthy discoveries.

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:57,971,703 XPM·at block #6,840,918 · updates every 60s
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