Block #566,545

2CCLength 11★★★☆☆

Cunningham Chain of the Second Kind · Discovered 5/29/2014, 12:12:55 AM · Difficulty 10.9660 · 6,225,803 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
948e887b0b54a1c2a3039251fd937931da6c1626d4ca27ac954be982bb8bbc91

Height

#566,545

Difficulty

10.965956

Transactions

5

Size

1.23 KB

Version

2

Bits

0af748e8

Nonce

1,639,788,776

Timestamp

5/29/2014, 12:12:55 AM

Confirmations

6,225,803

Merkle Root

fb16ef5760c7e28e8746f355f1faacee72b7e6a063e8e8acd88afa40031cd2ee
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.

7.762 × 10⁹⁹(100-digit number)
77627438027557564960…65473815921193861121
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
7.762 × 10⁹⁹(100-digit number)
77627438027557564960…65473815921193861121
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
1.552 × 10¹⁰⁰(101-digit number)
15525487605511512992…30947631842387722241
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
3.105 × 10¹⁰⁰(101-digit number)
31050975211023025984…61895263684775444481
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
6.210 × 10¹⁰⁰(101-digit number)
62101950422046051968…23790527369550888961
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
1.242 × 10¹⁰¹(102-digit number)
12420390084409210393…47581054739101777921
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
2.484 × 10¹⁰¹(102-digit number)
24840780168818420787…95162109478203555841
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
4.968 × 10¹⁰¹(102-digit number)
49681560337636841574…90324218956407111681
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
9.936 × 10¹⁰¹(102-digit number)
99363120675273683149…80648437912814223361
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
1.987 × 10¹⁰²(103-digit number)
19872624135054736629…61296875825628446721
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
3.974 × 10¹⁰²(103-digit number)
39745248270109473259…22593751651256893441
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
11
2^10 × origin + 1
7.949 × 10¹⁰²(103-digit number)
79490496540218946519…45187503302513786881
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:57,582,749 XPM·at block #6,792,347 · updates every 60s
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