Block #370,055

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 1/21/2014, 7:36:48 PM · Difficulty 10.4494 · 6,433,612 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
28c8bd7902b30c1272f37df2118af4953f89e65563f5a8ca7b0c38b0dcb8758f

Height

#370,055

Difficulty

10.449359

Transactions

6

Size

1.60 KB

Version

2

Bits

0a73092d

Nonce

5,290

Timestamp

1/21/2014, 7:36:48 PM

Confirmations

6,433,612

Merkle Root

2bfa98642717c3e94614f601cdc4db5daf092d63aed0596e09571e50f43b643f
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.

2.861 × 10⁹⁸(99-digit number)
28616140280728130583…73386652598790703039
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
2.861 × 10⁹⁸(99-digit number)
28616140280728130583…73386652598790703039
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
5.723 × 10⁹⁸(99-digit number)
57232280561456261167…46773305197581406079
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
1.144 × 10⁹⁹(100-digit number)
11446456112291252233…93546610395162812159
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
2.289 × 10⁹⁹(100-digit number)
22892912224582504466…87093220790325624319
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
4.578 × 10⁹⁹(100-digit number)
45785824449165008933…74186441580651248639
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
9.157 × 10⁹⁹(100-digit number)
91571648898330017867…48372883161302497279
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
1.831 × 10¹⁰⁰(101-digit number)
18314329779666003573…96745766322604994559
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
3.662 × 10¹⁰⁰(101-digit number)
36628659559332007147…93491532645209989119
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
7.325 × 10¹⁰⁰(101-digit number)
73257319118664014294…86983065290419978239
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
1.465 × 10¹⁰¹(102-digit number)
14651463823732802858…73966130580839956479
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:57,673,372 XPM·at block #6,803,666 · updates every 60s
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