Block #270,702

1CCLength 11★★★☆☆

Cunningham Chain of the First Kind · Discovered 11/24/2013, 3:40:36 AM · Difficulty 9.9515 · 6,543,383 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
1fbde6af33c23c5caa6352a3f7550343798bd2e391eedb7b3b82dbf17b06291e

Height

#270,702

Difficulty

9.951517

Transactions

1

Size

2.08 KB

Version

2

Bits

09f39698

Nonce

73,606

Timestamp

11/24/2013, 3:40:36 AM

Confirmations

6,543,383

Merkle Root

28433756fbc4cd08326231cf666c16d25a6540b64406c6c5b41648b4244054ba
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.

5.022 × 10⁹³(94-digit number)
50220033472016040592…79828824797522391039
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
5.022 × 10⁹³(94-digit number)
50220033472016040592…79828824797522391039
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
1.004 × 10⁹⁴(95-digit number)
10044006694403208118…59657649595044782079
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
2.008 × 10⁹⁴(95-digit number)
20088013388806416237…19315299190089564159
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
4.017 × 10⁹⁴(95-digit number)
40176026777612832474…38630598380179128319
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
8.035 × 10⁹⁴(95-digit number)
80352053555225664948…77261196760358256639
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
1.607 × 10⁹⁵(96-digit number)
16070410711045132989…54522393520716513279
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
3.214 × 10⁹⁵(96-digit number)
32140821422090265979…09044787041433026559
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
6.428 × 10⁹⁵(96-digit number)
64281642844180531958…18089574082866053119
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
1.285 × 10⁹⁶(97-digit number)
12856328568836106391…36179148165732106239
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
2.571 × 10⁹⁶(97-digit number)
25712657137672212783…72358296331464212479
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
11
2^10 × origin − 1
5.142 × 10⁹⁶(97-digit number)
51425314275344425567…44716592662928424959
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:57,756,761 XPM·at block #6,814,084 · updates every 60s
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