Block #346,361

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 1/6/2014, 12:12:12 PM · Difficulty 10.2269 · 6,462,064 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
7c0b66ec610ae0f6e2293feff0bac53de9b36ec7c72fef6505f00de37c9428e1

Height

#346,361

Difficulty

10.226896

Transactions

4

Size

1.71 KB

Version

2

Bits

0a3a15e2

Nonce

96,393

Timestamp

1/6/2014, 12:12:12 PM

Confirmations

6,462,064

Merkle Root

a15bd3ef5ea3678c2897450fe3b4258c8940baee649acaa38d5b42a114c74467
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.

4.317 × 10¹⁰⁰(101-digit number)
43175711782954239895…52342530195292287999
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
4.317 × 10¹⁰⁰(101-digit number)
43175711782954239895…52342530195292287999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
8.635 × 10¹⁰⁰(101-digit number)
86351423565908479791…04685060390584575999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
1.727 × 10¹⁰¹(102-digit number)
17270284713181695958…09370120781169151999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
3.454 × 10¹⁰¹(102-digit number)
34540569426363391916…18740241562338303999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
6.908 × 10¹⁰¹(102-digit number)
69081138852726783833…37480483124676607999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
1.381 × 10¹⁰²(103-digit number)
13816227770545356766…74960966249353215999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
2.763 × 10¹⁰²(103-digit number)
27632455541090713533…49921932498706431999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
5.526 × 10¹⁰²(103-digit number)
55264911082181427066…99843864997412863999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
1.105 × 10¹⁰³(104-digit number)
11052982216436285413…99687729994825727999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
2.210 × 10¹⁰³(104-digit number)
22105964432872570826…99375459989651455999
Verify on FactorDB ↗Wolfram Alpha ↗

What this block proved

The miner who found this block proved the existence of 10 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
UncommonChain length 10

Roughly 1 in 100 blocks. Solid but expected in a healthy network.

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:57,711,460 XPM·at block #6,808,424 · updates every 60s
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