Block #365,877

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 1/19/2014, 1:33:35 AM · Difficulty 10.4244 · 6,431,025 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
59ab44e4516d27fc523eadc699d9587ab39ecf9c363635519a15aa17bebecd6e

Height

#365,877

Difficulty

10.424400

Transactions

3

Size

8.67 KB

Version

2

Bits

0a6ca57c

Nonce

117,448,034

Timestamp

1/19/2014, 1:33:35 AM

Confirmations

6,431,025

Merkle Root

81f57c33ed16b134897fa21e7d134f2728ade9974de8528cc388e572f48ad0f8
Transactions (3)
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.

2.159 × 10⁹⁶(97-digit number)
21594890219122240718…97840592216048958719
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
2.159 × 10⁹⁶(97-digit number)
21594890219122240718…97840592216048958719
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
4.318 × 10⁹⁶(97-digit number)
43189780438244481437…95681184432097917439
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
8.637 × 10⁹⁶(97-digit number)
86379560876488962874…91362368864195834879
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
1.727 × 10⁹⁷(98-digit number)
17275912175297792574…82724737728391669759
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
3.455 × 10⁹⁷(98-digit number)
34551824350595585149…65449475456783339519
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
6.910 × 10⁹⁷(98-digit number)
69103648701191170299…30898950913566679039
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
1.382 × 10⁹⁸(99-digit number)
13820729740238234059…61797901827133358079
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
2.764 × 10⁹⁸(99-digit number)
27641459480476468119…23595803654266716159
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
5.528 × 10⁹⁸(99-digit number)
55282918960952936239…47191607308533432319
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
1.105 × 10⁹⁹(100-digit number)
11056583792190587247…94383214617066864639
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:57,619,237 XPM·at block #6,796,901 · updates every 60s
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