Block #365,595

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 1/18/2014, 9:01:58 PM · Difficulty 10.4231 · 6,427,459 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
04330a091949acef0db95b01d91d9febbf6ee60fbff35e12dac4dc92336d6069

Height

#365,595

Difficulty

10.423109

Transactions

5

Size

1.09 KB

Version

2

Bits

0a6c50e0

Nonce

97,293

Timestamp

1/18/2014, 9:01:58 PM

Confirmations

6,427,459

Merkle Root

e8c8002158243bffb3767ed2a997d159a6f0c58a1fd21c878d18652f3d0dbfcb
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.

4.296 × 10¹⁰⁵(106-digit number)
42966622560182042256…71884577420981204161
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
4.296 × 10¹⁰⁵(106-digit number)
42966622560182042256…71884577420981204161
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
8.593 × 10¹⁰⁵(106-digit number)
85933245120364084512…43769154841962408321
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
1.718 × 10¹⁰⁶(107-digit number)
17186649024072816902…87538309683924816641
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
3.437 × 10¹⁰⁶(107-digit number)
34373298048145633805…75076619367849633281
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
6.874 × 10¹⁰⁶(107-digit number)
68746596096291267610…50153238735699266561
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
1.374 × 10¹⁰⁷(108-digit number)
13749319219258253522…00306477471398533121
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
2.749 × 10¹⁰⁷(108-digit number)
27498638438516507044…00612954942797066241
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
5.499 × 10¹⁰⁷(108-digit number)
54997276877033014088…01225909885594132481
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
1.099 × 10¹⁰⁸(109-digit number)
10999455375406602817…02451819771188264961
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
2.199 × 10¹⁰⁸(109-digit number)
21998910750813205635…04903639542376529921
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:57,588,423 XPM·at block #6,793,053 · updates every 60s
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