Block #102,050

1CCLength 9★☆☆☆☆

Cunningham Chain of the First Kind · Discovered 8/6/2013, 11:02:57 PM · Difficulty 9.4798 · 6,702,748 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
8a43f03a3b81e6a8c52bc2e36d6effc275adee1303edd82f9f43780c683487dd

Height

#102,050

Difficulty

9.479849

Transactions

7

Size

3.11 KB

Version

2

Bits

097ad75c

Nonce

48,750

Timestamp

8/6/2013, 11:02:57 PM

Confirmations

6,702,748

Merkle Root

7ae64ca191d10f03d9723e7557cc728d9f96834fda2d7e5c6d30e95e057d4d0a
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.

1.101 × 10⁹⁴(95-digit number)
11015371537490676688…38031729678455443879
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
1.101 × 10⁹⁴(95-digit number)
11015371537490676688…38031729678455443879
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
2.203 × 10⁹⁴(95-digit number)
22030743074981353376…76063459356910887759
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
4.406 × 10⁹⁴(95-digit number)
44061486149962706752…52126918713821775519
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
8.812 × 10⁹⁴(95-digit number)
88122972299925413504…04253837427643551039
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
1.762 × 10⁹⁵(96-digit number)
17624594459985082700…08507674855287102079
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
3.524 × 10⁹⁵(96-digit number)
35249188919970165401…17015349710574204159
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
7.049 × 10⁹⁵(96-digit number)
70498377839940330803…34030699421148408319
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
1.409 × 10⁹⁶(97-digit number)
14099675567988066160…68061398842296816639
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
2.819 × 10⁹⁶(97-digit number)
28199351135976132321…36122797684593633279
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:57,682,451 XPM·at block #6,804,797 · updates every 60s
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