Block #578,038

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 6/5/2014, 6:10:27 PM · Difficulty 10.9685 · 6,216,133 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
a687f7d1a89615d1861908cf783f231ec1a1bdc7cb6318ef78b136b6db9efecc

Height

#578,038

Difficulty

10.968493

Transactions

7

Size

1.53 KB

Version

2

Bits

0af7ef21

Nonce

72,885,939

Timestamp

6/5/2014, 6:10:27 PM

Confirmations

6,216,133

Merkle Root

e53027822502b3d38b1f55f49566ad512c6a5c45ced0c39bd6e475814877fde4
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.

1.212 × 10⁹⁹(100-digit number)
12127541637710708018…10486510514440313601
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
1.212 × 10⁹⁹(100-digit number)
12127541637710708018…10486510514440313601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
2.425 × 10⁹⁹(100-digit number)
24255083275421416037…20973021028880627201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
4.851 × 10⁹⁹(100-digit number)
48510166550842832075…41946042057761254401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
9.702 × 10⁹⁹(100-digit number)
97020333101685664150…83892084115522508801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
1.940 × 10¹⁰⁰(101-digit number)
19404066620337132830…67784168231045017601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
3.880 × 10¹⁰⁰(101-digit number)
38808133240674265660…35568336462090035201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
7.761 × 10¹⁰⁰(101-digit number)
77616266481348531320…71136672924180070401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
1.552 × 10¹⁰¹(102-digit number)
15523253296269706264…42273345848360140801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
3.104 × 10¹⁰¹(102-digit number)
31046506592539412528…84546691696720281601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
6.209 × 10¹⁰¹(102-digit number)
62093013185078825056…69093383393440563201
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 Second 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 2CC formula:

2CC: p₁ (first prime), p₂ = 2p₁ − 1, p₃ = 2p₂ − 1, …
Circulating Supply:57,597,391 XPM·at block #6,794,170 · updates every 60s
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