Block #450,590

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 3/19/2014, 9:47:03 AM · Difficulty 10.3720 · 6,342,252 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
3b5e99254f14babafa856f2adeec5061255b243de69408ed0831d7d2204a82ad

Height

#450,590

Difficulty

10.372029

Transactions

3

Size

2.14 KB

Version

2

Bits

0a5f3d43

Nonce

31,338

Timestamp

3/19/2014, 9:47:03 AM

Confirmations

6,342,252

Merkle Root

1df68c1720dfc8506d56c5be50982bd717949e7f60edc82827f4bab11ebb012e
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.

3.080 × 10¹⁰¹(102-digit number)
30803164788198615324…59920327574379238401
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
3.080 × 10¹⁰¹(102-digit number)
30803164788198615324…59920327574379238401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
6.160 × 10¹⁰¹(102-digit number)
61606329576397230648…19840655148758476801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
1.232 × 10¹⁰²(103-digit number)
12321265915279446129…39681310297516953601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
2.464 × 10¹⁰²(103-digit number)
24642531830558892259…79362620595033907201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
4.928 × 10¹⁰²(103-digit number)
49285063661117784519…58725241190067814401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
9.857 × 10¹⁰²(103-digit number)
98570127322235569038…17450482380135628801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
1.971 × 10¹⁰³(104-digit number)
19714025464447113807…34900964760271257601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
3.942 × 10¹⁰³(104-digit number)
39428050928894227615…69801929520542515201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
7.885 × 10¹⁰³(104-digit number)
78856101857788455230…39603859041085030401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
1.577 × 10¹⁰⁴(105-digit number)
15771220371557691046…79207718082170060801
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:57,586,716 XPM·at block #6,792,841 · updates every 60s
xpmprime.info is a work in progress. If you enjoy using this service you can support this project with a Primecoin donation.