Block #350,848

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 1/9/2014, 8:14:00 AM · Difficulty 10.2873 · 6,447,832 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
7e3ccd146c3e19be96d6980f6454ae51d2f2d1c7bd39abc7fa8ae140cffe0629

Height

#350,848

Difficulty

10.287288

Transactions

6

Size

1.88 KB

Version

2

Bits

0a498bb7

Nonce

49,332

Timestamp

1/9/2014, 8:14:00 AM

Confirmations

6,447,832

Merkle Root

7709b6b1f168c3e5dd1bde332b4dd0eb1948ef34f018c7077003848891a60dfa
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.

1.205 × 10⁹⁸(99-digit number)
12059855595442358678…75573096544055128319
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
1.205 × 10⁹⁸(99-digit number)
12059855595442358678…75573096544055128319
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
2.411 × 10⁹⁸(99-digit number)
24119711190884717356…51146193088110256639
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
4.823 × 10⁹⁸(99-digit number)
48239422381769434712…02292386176220513279
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
9.647 × 10⁹⁸(99-digit number)
96478844763538869424…04584772352441026559
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
1.929 × 10⁹⁹(100-digit number)
19295768952707773884…09169544704882053119
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
3.859 × 10⁹⁹(100-digit number)
38591537905415547769…18339089409764106239
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
7.718 × 10⁹⁹(100-digit number)
77183075810831095539…36678178819528212479
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
1.543 × 10¹⁰⁰(101-digit number)
15436615162166219107…73356357639056424959
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
3.087 × 10¹⁰⁰(101-digit number)
30873230324332438215…46712715278112849919
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
6.174 × 10¹⁰⁰(101-digit number)
61746460648664876431…93425430556225699839
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:57,633,467 XPM·at block #6,798,679 · updates every 60s
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