Block #435,716

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 3/9/2014, 3:24:39 AM · Difficulty 10.3519 · 6,358,946 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
653ecb492a7c53fb2ec085f0274ebe8704b5788e54c0835a2491110cf97f3e01

Height

#435,716

Difficulty

10.351884

Transactions

2

Size

417 B

Version

2

Bits

0a5a1511

Nonce

108,608

Timestamp

3/9/2014, 3:24:39 AM

Confirmations

6,358,946

Merkle Root

1d7cf57d950ca0c64de803d3fa12003826deae33869c32c4a0700cc1b89b9b74
Transactions (2)
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.

1.621 × 10⁹⁶(97-digit number)
16210147285570917322…22704050513217196799
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
1.621 × 10⁹⁶(97-digit number)
16210147285570917322…22704050513217196799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
3.242 × 10⁹⁶(97-digit number)
32420294571141834644…45408101026434393599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
6.484 × 10⁹⁶(97-digit number)
64840589142283669289…90816202052868787199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
1.296 × 10⁹⁷(98-digit number)
12968117828456733857…81632404105737574399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
2.593 × 10⁹⁷(98-digit number)
25936235656913467715…63264808211475148799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
5.187 × 10⁹⁷(98-digit number)
51872471313826935431…26529616422950297599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
1.037 × 10⁹⁸(99-digit number)
10374494262765387086…53059232845900595199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
2.074 × 10⁹⁸(99-digit number)
20748988525530774172…06118465691801190399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
4.149 × 10⁹⁸(99-digit number)
41497977051061548345…12236931383602380799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
8.299 × 10⁹⁸(99-digit number)
82995954102123096690…24473862767204761599
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:57,601,345 XPM·at block #6,794,661 · updates every 60s
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