Block #2,469,305

1CCLength 11★★★☆☆

Cunningham Chain of the First Kind · Discovered 1/12/2018, 10:32:16 AM · Difficulty 10.9600 · 4,336,881 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
f6a8d2d934484f0c9268ac0a2e2d4f3e6805735cac80d12941e6890d98feb83e

Height

#2,469,305

Difficulty

10.960027

Transactions

3

Size

801 B

Version

2

Bits

0af5c45a

Nonce

340,526,486

Timestamp

1/12/2018, 10:32:16 AM

Confirmations

4,336,881

Merkle Root

9cb15cc3af84fa5d3cf647b70d50079c32984c89024e7177f70e3a1f123fb241
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.

5.247 × 10⁹⁴(95-digit number)
52470437503050330399…15313704201240821999
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
5.247 × 10⁹⁴(95-digit number)
52470437503050330399…15313704201240821999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
1.049 × 10⁹⁵(96-digit number)
10494087500610066079…30627408402481643999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
2.098 × 10⁹⁵(96-digit number)
20988175001220132159…61254816804963287999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
4.197 × 10⁹⁵(96-digit number)
41976350002440264319…22509633609926575999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
8.395 × 10⁹⁵(96-digit number)
83952700004880528638…45019267219853151999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
1.679 × 10⁹⁶(97-digit number)
16790540000976105727…90038534439706303999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
3.358 × 10⁹⁶(97-digit number)
33581080001952211455…80077068879412607999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
6.716 × 10⁹⁶(97-digit number)
67162160003904422911…60154137758825215999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
1.343 × 10⁹⁷(98-digit number)
13432432000780884582…20308275517650431999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
2.686 × 10⁹⁷(98-digit number)
26864864001561769164…40616551035300863999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
11
2^10 × origin − 1
5.372 × 10⁹⁷(98-digit number)
53729728003123538328…81233102070601727999
Verify on FactorDB ↗Wolfram Alpha ↗

What this block proved

The miner who found this block proved the existence of 11 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
RareChain length 11

Approximately 1 in 1,000 blocks. Noteworthy discoveries.

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:57,693,573 XPM·at block #6,806,185 · updates every 60s
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