Block #102,524

1CCLength 9★☆☆☆☆

Cunningham Chain of the First Kind · Discovered 8/7/2013, 4:16:18 AM · Difficulty 9.4964 · 6,701,365 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
cacd9f5da27e872c529d668f425974649ea93fd6cf877d06332eddcf6ed5b2db

Height

#102,524

Difficulty

9.496433

Transactions

5

Size

1.66 KB

Version

2

Bits

097f163a

Nonce

131,818

Timestamp

8/7/2013, 4:16:18 AM

Confirmations

6,701,365

Merkle Root

492d40cacab5adf1f5da1a08b987e763feefb302f867b78d8baa29ed853d397c
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.

1.017 × 10⁹⁷(98-digit number)
10171479610250398263…84369164398100763379
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
1.017 × 10⁹⁷(98-digit number)
10171479610250398263…84369164398100763379
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
2.034 × 10⁹⁷(98-digit number)
20342959220500796526…68738328796201526759
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
4.068 × 10⁹⁷(98-digit number)
40685918441001593052…37476657592403053519
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
8.137 × 10⁹⁷(98-digit number)
81371836882003186105…74953315184806107039
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
1.627 × 10⁹⁸(99-digit number)
16274367376400637221…49906630369612214079
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
3.254 × 10⁹⁸(99-digit number)
32548734752801274442…99813260739224428159
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
6.509 × 10⁹⁸(99-digit number)
65097469505602548884…99626521478448856319
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
1.301 × 10⁹⁹(100-digit number)
13019493901120509776…99253042956897712639
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
2.603 × 10⁹⁹(100-digit number)
26038987802241019553…98506085913795425279
Verify on FactorDB ↗Wolfram Alpha ↗

What this block proved

The miner who found this block proved the existence of 9 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
CommonChain length 9

Found in most blocks. The baseline for Primecoin's proof-of-work.

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:57,675,156 XPM·at block #6,803,888 · updates every 60s
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