Block #374,324

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 1/24/2014, 10:41:05 PM · Difficulty 10.4247 · 6,423,341 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
f644dda6b2124f4e1f83f7c08e7fd7601cd14fee85b45da3e059779adf73c5cb

Height

#374,324

Difficulty

10.424652

Transactions

5

Size

1.22 KB

Version

2

Bits

0a6cb604

Nonce

122,631

Timestamp

1/24/2014, 10:41:05 PM

Confirmations

6,423,341

Merkle Root

1fbc0349ec118227f2c63edd48efe2f5ddcb1ec5585782bf4c41cc02a93ba46d
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.

5.458 × 10⁹⁴(95-digit number)
54583430276977996378…53214070465720114331
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
5.458 × 10⁹⁴(95-digit number)
54583430276977996378…53214070465720114331
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
1.091 × 10⁹⁵(96-digit number)
10916686055395599275…06428140931440228661
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
2.183 × 10⁹⁵(96-digit number)
21833372110791198551…12856281862880457321
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
4.366 × 10⁹⁵(96-digit number)
43666744221582397102…25712563725760914641
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
8.733 × 10⁹⁵(96-digit number)
87333488443164794205…51425127451521829281
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
1.746 × 10⁹⁶(97-digit number)
17466697688632958841…02850254903043658561
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
3.493 × 10⁹⁶(97-digit number)
34933395377265917682…05700509806087317121
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
6.986 × 10⁹⁶(97-digit number)
69866790754531835364…11401019612174634241
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
1.397 × 10⁹⁷(98-digit number)
13973358150906367072…22802039224349268481
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
2.794 × 10⁹⁷(98-digit number)
27946716301812734145…45604078448698536961
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:57,625,312 XPM·at block #6,797,664 · updates every 60s
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