Block #470,098

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 4/1/2014, 4:25:16 PM · Difficulty 10.4310 · 6,340,993 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
d5d53874ec58504e20f878c7e29ecdd5bcc5b763201a8caf6eab2026fc6d557a

Height

#470,098

Difficulty

10.430977

Transactions

1

Size

1003 B

Version

2

Bits

0a6e547a

Nonce

269,792

Timestamp

4/1/2014, 4:25:16 PM

Confirmations

6,340,993

Merkle Root

23e9960f7c936cc2f1fe900bf6a90ef1aac7e983aa438a37b42fb91dd1246b59
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.

1.386 × 10⁹⁴(95-digit number)
13861201173383224279…10049793483182784481
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
1.386 × 10⁹⁴(95-digit number)
13861201173383224279…10049793483182784481
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
2.772 × 10⁹⁴(95-digit number)
27722402346766448558…20099586966365568961
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
5.544 × 10⁹⁴(95-digit number)
55444804693532897116…40199173932731137921
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
1.108 × 10⁹⁵(96-digit number)
11088960938706579423…80398347865462275841
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
2.217 × 10⁹⁵(96-digit number)
22177921877413158846…60796695730924551681
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
4.435 × 10⁹⁵(96-digit number)
44355843754826317693…21593391461849103361
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
8.871 × 10⁹⁵(96-digit number)
88711687509652635386…43186782923698206721
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
1.774 × 10⁹⁶(97-digit number)
17742337501930527077…86373565847396413441
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
3.548 × 10⁹⁶(97-digit number)
35484675003861054154…72747131694792826881
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
7.096 × 10⁹⁶(97-digit number)
70969350007722108308…45494263389585653761
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:57,732,835 XPM·at block #6,811,090 · 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.

Cookie Preferences

We use cookies to enhance your experience. Some are essential for the site to function, while others help us understand how you use the site.

·Privacy Policy