Block #368,372

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 1/20/2014, 4:45:39 PM · Difficulty 10.4412 · 6,457,740 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
25cc7be038e693652f214c47b6c440464f0b905f686326ee5e2a1d68134de248

Height

#368,372

Difficulty

10.441211

Transactions

1

Size

1003 B

Version

2

Bits

0a70f337

Nonce

28,437

Timestamp

1/20/2014, 4:45:39 PM

Confirmations

6,457,740

Merkle Root

17d84e6176eac7657ea7069de68c1010881110e51300b63951f08feabee3a9fe
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.

4.553 × 10⁹⁴(95-digit number)
45531204102790205146…44179192688954265601
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
4.553 × 10⁹⁴(95-digit number)
45531204102790205146…44179192688954265601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
9.106 × 10⁹⁴(95-digit number)
91062408205580410292…88358385377908531201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
1.821 × 10⁹⁵(96-digit number)
18212481641116082058…76716770755817062401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
3.642 × 10⁹⁵(96-digit number)
36424963282232164116…53433541511634124801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
7.284 × 10⁹⁵(96-digit number)
72849926564464328233…06867083023268249601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
1.456 × 10⁹⁶(97-digit number)
14569985312892865646…13734166046536499201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
2.913 × 10⁹⁶(97-digit number)
29139970625785731293…27468332093072998401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
5.827 × 10⁹⁶(97-digit number)
58279941251571462586…54936664186145996801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
1.165 × 10⁹⁷(98-digit number)
11655988250314292517…09873328372291993601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
2.331 × 10⁹⁷(98-digit number)
23311976500628585034…19746656744583987201
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:57,853,020 XPM·at block #6,826,111 · updates every 60s
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