Block #580,450

2CCLength 11★★★☆☆

Cunningham Chain of the Second Kind · Discovered 6/7/2014, 7:25:25 PM · Difficulty 10.9650 · 6,227,672 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
64760f0b5e98a5cfdfcee6330b47d353e4448aff9b22ae6b9ee84cccfccb4f93

Height

#580,450

Difficulty

10.964966

Transactions

3

Size

1.80 KB

Version

2

Bits

0af70802

Nonce

72,173,870

Timestamp

6/7/2014, 7:25:25 PM

Confirmations

6,227,672

Merkle Root

05675b47a771ba54441b4d87a5eb6bccd96676e0df9100da4868362c4614ac88
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.

5.825 × 10⁹⁹(100-digit number)
58250712079840544635…95760082405399930881
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
5.825 × 10⁹⁹(100-digit number)
58250712079840544635…95760082405399930881
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
1.165 × 10¹⁰⁰(101-digit number)
11650142415968108927…91520164810799861761
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
2.330 × 10¹⁰⁰(101-digit number)
23300284831936217854…83040329621599723521
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
4.660 × 10¹⁰⁰(101-digit number)
46600569663872435708…66080659243199447041
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
9.320 × 10¹⁰⁰(101-digit number)
93201139327744871417…32161318486398894081
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
1.864 × 10¹⁰¹(102-digit number)
18640227865548974283…64322636972797788161
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
3.728 × 10¹⁰¹(102-digit number)
37280455731097948566…28645273945595576321
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
7.456 × 10¹⁰¹(102-digit number)
74560911462195897133…57290547891191152641
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
1.491 × 10¹⁰²(103-digit number)
14912182292439179426…14581095782382305281
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
2.982 × 10¹⁰²(103-digit number)
29824364584878358853…29162191564764610561
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
11
2^10 × origin + 1
5.964 × 10¹⁰²(103-digit number)
59648729169756717706…58324383129529221121
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 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
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 2CC formula:

2CC: p₁ (first prime), p₂ = 2p₁ − 1, p₃ = 2p₂ − 1, …
Circulating Supply:57,709,016 XPM·at block #6,808,121 · updates every 60s
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