Block #591,076

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 6/16/2014, 6:49:39 PM · Difficulty 10.9452 · 6,226,927 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
4e7855cf1d7b1b419b4826322848a02eeb41bd87b767043ff7e12ce6c06e7321

Height

#591,076

Difficulty

10.945186

Transactions

4

Size

1.73 KB

Version

2

Bits

0af1f7ba

Nonce

28,825,006

Timestamp

6/16/2014, 6:49:39 PM

Confirmations

6,226,927

Merkle Root

e6408f94a39ba471f59f26efed270bc57745d17e6adf1008daa1ece54b16d267
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.

5.749 × 10⁹⁶(97-digit number)
57491181905451960632…35608484400618907541
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
5.749 × 10⁹⁶(97-digit number)
57491181905451960632…35608484400618907541
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
1.149 × 10⁹⁷(98-digit number)
11498236381090392126…71216968801237815081
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
2.299 × 10⁹⁷(98-digit number)
22996472762180784252…42433937602475630161
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
4.599 × 10⁹⁷(98-digit number)
45992945524361568505…84867875204951260321
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
9.198 × 10⁹⁷(98-digit number)
91985891048723137011…69735750409902520641
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
1.839 × 10⁹⁸(99-digit number)
18397178209744627402…39471500819805041281
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
3.679 × 10⁹⁸(99-digit number)
36794356419489254804…78943001639610082561
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
7.358 × 10⁹⁸(99-digit number)
73588712838978509609…57886003279220165121
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
1.471 × 10⁹⁹(100-digit number)
14717742567795701921…15772006558440330241
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
2.943 × 10⁹⁹(100-digit number)
29435485135591403843…31544013116880660481
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:57,788,089 XPM·at block #6,818,002 · updates every 60s
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