Block #359,959

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 1/15/2014, 3:46:20 AM · Difficulty 10.3880 · 6,432,165 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
ed32e915a6ef611412845842432e60458e320c4a5138b7cb8319e7a6f22bb58d

Height

#359,959

Difficulty

10.387995

Transactions

9

Size

2.22 KB

Version

2

Bits

0a6353a0

Nonce

70,284

Timestamp

1/15/2014, 3:46:20 AM

Confirmations

6,432,165

Merkle Root

4e2ea2a26d5b00935a245e56571ebc650fb2027fc5ae479b0411f22fde893741
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.

1.019 × 10¹⁰⁰(101-digit number)
10197503898251933021…14065821780155531841
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
1.019 × 10¹⁰⁰(101-digit number)
10197503898251933021…14065821780155531841
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
2.039 × 10¹⁰⁰(101-digit number)
20395007796503866043…28131643560311063681
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
4.079 × 10¹⁰⁰(101-digit number)
40790015593007732086…56263287120622127361
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
8.158 × 10¹⁰⁰(101-digit number)
81580031186015464173…12526574241244254721
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
1.631 × 10¹⁰¹(102-digit number)
16316006237203092834…25053148482488509441
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
3.263 × 10¹⁰¹(102-digit number)
32632012474406185669…50106296964977018881
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
6.526 × 10¹⁰¹(102-digit number)
65264024948812371338…00212593929954037761
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
1.305 × 10¹⁰²(103-digit number)
13052804989762474267…00425187859908075521
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
2.610 × 10¹⁰²(103-digit number)
26105609979524948535…00850375719816151041
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
5.221 × 10¹⁰²(103-digit number)
52211219959049897071…01700751439632302081
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:57,580,943 XPM·at block #6,792,123 · updates every 60s
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