Block #234,344

1CCLength 9★☆☆☆☆

Cunningham Chain of the First Kind · Discovered 10/30/2013, 6:42:28 AM · Difficulty 9.9440 · 6,562,407 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
d4e8034b0a25ed1cb31babd438a837601e9b1207be534abd0a1bbeb39b0c3754

Height

#234,344

Difficulty

9.943966

Transactions

5

Size

1.22 KB

Version

2

Bits

09f1a7c2

Nonce

4,913

Timestamp

10/30/2013, 6:42:28 AM

Confirmations

6,562,407

Merkle Root

36f85686ef2350be6627b843d1fb5bcfbeb4ebfc05a7550558d802cb4e7d966d
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.

2.064 × 10⁹⁴(95-digit number)
20648787245668580887…37858727821853309439
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
2.064 × 10⁹⁴(95-digit number)
20648787245668580887…37858727821853309439
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
4.129 × 10⁹⁴(95-digit number)
41297574491337161774…75717455643706618879
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
8.259 × 10⁹⁴(95-digit number)
82595148982674323549…51434911287413237759
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
1.651 × 10⁹⁵(96-digit number)
16519029796534864709…02869822574826475519
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
3.303 × 10⁹⁵(96-digit number)
33038059593069729419…05739645149652951039
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
6.607 × 10⁹⁵(96-digit number)
66076119186139458839…11479290299305902079
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
1.321 × 10⁹⁶(97-digit number)
13215223837227891767…22958580598611804159
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
2.643 × 10⁹⁶(97-digit number)
26430447674455783535…45917161197223608319
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
5.286 × 10⁹⁶(97-digit number)
52860895348911567071…91834322394447216639
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:57,618,016 XPM·at block #6,796,750 · updates every 60s
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