Block #379,880

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 1/28/2014, 8:05:02 PM · Difficulty 10.4201 · 6,415,895 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
f4baf4a67c8c22d062d9ec64671a69dab6dc399be085cfca694ad39e78bf1f50

Height

#379,880

Difficulty

10.420149

Transactions

5

Size

1.08 KB

Version

2

Bits

0a6b8ee2

Nonce

107,922

Timestamp

1/28/2014, 8:05:02 PM

Confirmations

6,415,895

Merkle Root

4a12333c75cce9c06e6fa7a073055766e074c73d944504c724d418956b98a77f
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.

8.414 × 10⁹⁵(96-digit number)
84147975449513130695…53702229247732106239
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
8.414 × 10⁹⁵(96-digit number)
84147975449513130695…53702229247732106239
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
1.682 × 10⁹⁶(97-digit number)
16829595089902626139…07404458495464212479
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
3.365 × 10⁹⁶(97-digit number)
33659190179805252278…14808916990928424959
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
6.731 × 10⁹⁶(97-digit number)
67318380359610504556…29617833981856849919
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
1.346 × 10⁹⁷(98-digit number)
13463676071922100911…59235667963713699839
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
2.692 × 10⁹⁷(98-digit number)
26927352143844201822…18471335927427399679
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
5.385 × 10⁹⁷(98-digit number)
53854704287688403644…36942671854854799359
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
1.077 × 10⁹⁸(99-digit number)
10770940857537680728…73885343709709598719
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
2.154 × 10⁹⁸(99-digit number)
21541881715075361457…47770687419419197439
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
4.308 × 10⁹⁸(99-digit number)
43083763430150722915…95541374838838394879
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:57,610,276 XPM·at block #6,795,774 · updates every 60s
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