Block #370,667

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 1/22/2014, 7:40:01 AM · Difficulty 10.4374 · 6,426,216 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
f3b35deb0c80fb31ca9526cba6659594989f427a769e374edebf36efd11f7b7a

Height

#370,667

Difficulty

10.437363

Transactions

6

Size

2.33 KB

Version

2

Bits

0a6ff703

Nonce

7,038

Timestamp

1/22/2014, 7:40:01 AM

Confirmations

6,426,216

Merkle Root

ff0e1030a5d561acc211d4bb868fe0b4ae609164117b8c0c8fd8539748189e4b
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.

8.441 × 10⁹⁹(100-digit number)
84419328917534328508…62859543665760144759
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
8.441 × 10⁹⁹(100-digit number)
84419328917534328508…62859543665760144759
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
1.688 × 10¹⁰⁰(101-digit number)
16883865783506865701…25719087331520289519
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
3.376 × 10¹⁰⁰(101-digit number)
33767731567013731403…51438174663040579039
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
6.753 × 10¹⁰⁰(101-digit number)
67535463134027462807…02876349326081158079
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
1.350 × 10¹⁰¹(102-digit number)
13507092626805492561…05752698652162316159
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
2.701 × 10¹⁰¹(102-digit number)
27014185253610985122…11505397304324632319
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
5.402 × 10¹⁰¹(102-digit number)
54028370507221970245…23010794608649264639
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
1.080 × 10¹⁰²(103-digit number)
10805674101444394049…46021589217298529279
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
2.161 × 10¹⁰²(103-digit number)
21611348202888788098…92043178434597058559
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
4.322 × 10¹⁰²(103-digit number)
43222696405777576196…84086356869194117119
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:57,619,081 XPM·at block #6,796,882 · updates every 60s
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