Block #364,218

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 1/17/2014, 10:23:13 PM · Difficulty 10.4202 · 6,438,548 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
5da117501c889f6eb249d508657c48c40818f3134ee3049130738dd819faa867

Height

#364,218

Difficulty

10.420174

Transactions

2

Size

404 B

Version

2

Bits

0a6b9089

Nonce

321,378

Timestamp

1/17/2014, 10:23:13 PM

Confirmations

6,438,548

Merkle Root

41ca8ce227308ee2d9ae2f63e03f87459d5c3a0617581d0b346b6f69f18953a9
Transactions (2)
1 in → 1 out9.2100 XPM116 B
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.

4.408 × 10¹⁰⁵(106-digit number)
44083639513621075559…91726472675045560319
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
4.408 × 10¹⁰⁵(106-digit number)
44083639513621075559…91726472675045560319
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
8.816 × 10¹⁰⁵(106-digit number)
88167279027242151119…83452945350091120639
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
1.763 × 10¹⁰⁶(107-digit number)
17633455805448430223…66905890700182241279
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
3.526 × 10¹⁰⁶(107-digit number)
35266911610896860447…33811781400364482559
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
7.053 × 10¹⁰⁶(107-digit number)
70533823221793720895…67623562800728965119
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
1.410 × 10¹⁰⁷(108-digit number)
14106764644358744179…35247125601457930239
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
2.821 × 10¹⁰⁷(108-digit number)
28213529288717488358…70494251202915860479
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
5.642 × 10¹⁰⁷(108-digit number)
56427058577434976716…40988502405831720959
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
1.128 × 10¹⁰⁸(109-digit number)
11285411715486995343…81977004811663441919
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
2.257 × 10¹⁰⁸(109-digit number)
22570823430973990686…63954009623326883839
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:57,666,152 XPM·at block #6,802,765 · updates every 60s
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