Block #374,773

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 1/25/2014, 6:57:36 AM · Difficulty 10.4194 · 6,430,390 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
7339996c6b5ea6464dc10032cbe804c7c0c3d29212f1ac7cffdd8169aebf30b9

Height

#374,773

Difficulty

10.419397

Transactions

6

Size

2.32 KB

Version

2

Bits

0a6b5da0

Nonce

167,772,370

Timestamp

1/25/2014, 6:57:36 AM

Confirmations

6,430,390

Merkle Root

58f442dfea370d1e46c78266ad62cc3db048572ad80e4633ba631d186146845f
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.

1.410 × 10⁹⁵(96-digit number)
14104099808953050627…48681844351818603999
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
1.410 × 10⁹⁵(96-digit number)
14104099808953050627…48681844351818603999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
2.820 × 10⁹⁵(96-digit number)
28208199617906101255…97363688703637207999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
5.641 × 10⁹⁵(96-digit number)
56416399235812202511…94727377407274415999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
1.128 × 10⁹⁶(97-digit number)
11283279847162440502…89454754814548831999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
2.256 × 10⁹⁶(97-digit number)
22566559694324881004…78909509629097663999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
4.513 × 10⁹⁶(97-digit number)
45133119388649762009…57819019258195327999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
9.026 × 10⁹⁶(97-digit number)
90266238777299524019…15638038516390655999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
1.805 × 10⁹⁷(98-digit number)
18053247755459904803…31276077032781311999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
3.610 × 10⁹⁷(98-digit number)
36106495510919809607…62552154065562623999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
7.221 × 10⁹⁷(98-digit number)
72212991021839619215…25104308131125247999
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 First 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 1CC formula:

1CC: p₁ (first prime), p₂ = 2p₁ + 1, p₃ = 2p₂ + 1, …
Circulating Supply:57,685,371 XPM·at block #6,805,162 · updates every 60s
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