Block #360,767

2CCLength 11★★★☆☆

Cunningham Chain of the Second Kind · Discovered 1/15/2014, 3:45:53 PM · Difficulty 10.3985 · 6,454,175 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
e90cae3d3265c5242ff20da7be0761500a7a414fc29d45ef29d812d40a062795

Height

#360,767

Difficulty

10.398507

Transactions

8

Size

2.91 KB

Version

2

Bits

0a660494

Nonce

11,414

Timestamp

1/15/2014, 3:45:53 PM

Confirmations

6,454,175

Merkle Root

5a6946d66214b11906dac51f07eb441cb8c066079ac06cca1434b3bb095d15e8
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.

1.445 × 10¹⁰²(103-digit number)
14452693150849091608…74189081243128118121
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
1.445 × 10¹⁰²(103-digit number)
14452693150849091608…74189081243128118121
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
2.890 × 10¹⁰²(103-digit number)
28905386301698183216…48378162486256236241
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
5.781 × 10¹⁰²(103-digit number)
57810772603396366432…96756324972512472481
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
1.156 × 10¹⁰³(104-digit number)
11562154520679273286…93512649945024944961
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
2.312 × 10¹⁰³(104-digit number)
23124309041358546573…87025299890049889921
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
4.624 × 10¹⁰³(104-digit number)
46248618082717093146…74050599780099779841
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
9.249 × 10¹⁰³(104-digit number)
92497236165434186292…48101199560199559681
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
1.849 × 10¹⁰⁴(105-digit number)
18499447233086837258…96202399120399119361
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
3.699 × 10¹⁰⁴(105-digit number)
36998894466173674516…92404798240798238721
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
7.399 × 10¹⁰⁴(105-digit number)
73997788932347349033…84809596481596477441
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
11
2^10 × origin + 1
1.479 × 10¹⁰⁵(106-digit number)
14799557786469469806…69619192963192954881
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:57,763,632 XPM·at block #6,814,941 · updates every 60s
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