Block #346,496

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 1/6/2014, 2:27:26 PM · Difficulty 10.2269 · 6,449,623 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
6bd71b4b6ca4df0dcc60d19aa2e5d485df25c71520739b9fe9fd614b02c52232

Height

#346,496

Difficulty

10.226927

Transactions

3

Size

946 B

Version

2

Bits

0a3a17e5

Nonce

218,003

Timestamp

1/6/2014, 2:27:26 PM

Confirmations

6,449,623

Merkle Root

caa3fa9d793e73a099402b2c624cb8c6c361becf019992fca03e768a93a7a558
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.

4.773 × 10⁹³(94-digit number)
47737187801929449578…47293440332823193599
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
4.773 × 10⁹³(94-digit number)
47737187801929449578…47293440332823193599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
9.547 × 10⁹³(94-digit number)
95474375603858899157…94586880665646387199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
1.909 × 10⁹⁴(95-digit number)
19094875120771779831…89173761331292774399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
3.818 × 10⁹⁴(95-digit number)
38189750241543559662…78347522662585548799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
7.637 × 10⁹⁴(95-digit number)
76379500483087119325…56695045325171097599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
1.527 × 10⁹⁵(96-digit number)
15275900096617423865…13390090650342195199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
3.055 × 10⁹⁵(96-digit number)
30551800193234847730…26780181300684390399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
6.110 × 10⁹⁵(96-digit number)
61103600386469695460…53560362601368780799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
1.222 × 10⁹⁶(97-digit number)
12220720077293939092…07120725202737561599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
2.444 × 10⁹⁶(97-digit number)
24441440154587878184…14241450405475123199
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:57,612,948 XPM·at block #6,796,118 · updates every 60s
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