Block #453,520

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 3/21/2014, 9:12:29 AM · Difficulty 10.3848 · 6,352,503 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
a26fbe690bb7572d1b97f5d7ee86887eaf3d92dbe3d473a24dbd3bc0d88c883e

Height

#453,520

Difficulty

10.384785

Transactions

17

Size

4.96 KB

Version

2

Bits

0a628141

Nonce

88,029

Timestamp

3/21/2014, 9:12:29 AM

Confirmations

6,352,503

Merkle Root

7da24b8a9bbfcb427ddff055791bc5e138c86d0249904e7b80724fd85998ea15
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.

3.970 × 10⁹⁷(98-digit number)
39701579344350318858…31364043377927807149
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
3.970 × 10⁹⁷(98-digit number)
39701579344350318858…31364043377927807149
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
7.940 × 10⁹⁷(98-digit number)
79403158688700637717…62728086755855614299
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
1.588 × 10⁹⁸(99-digit number)
15880631737740127543…25456173511711228599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
3.176 × 10⁹⁸(99-digit number)
31761263475480255087…50912347023422457199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
6.352 × 10⁹⁸(99-digit number)
63522526950960510174…01824694046844914399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
1.270 × 10⁹⁹(100-digit number)
12704505390192102034…03649388093689828799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
2.540 × 10⁹⁹(100-digit number)
25409010780384204069…07298776187379657599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
5.081 × 10⁹⁹(100-digit number)
50818021560768408139…14597552374759315199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
1.016 × 10¹⁰⁰(101-digit number)
10163604312153681627…29195104749518630399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
2.032 × 10¹⁰⁰(101-digit number)
20327208624307363255…58390209499037260799
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:57,692,262 XPM·at block #6,806,022 · updates every 60s
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