Block #375,634

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 1/25/2014, 8:30:41 PM · Difficulty 10.4247 · 6,437,316 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
0883b114f31773f0f2cbb424e0994df78ac1a71cae99156e4f5e3987c8ac7b56

Height

#375,634

Difficulty

10.424705

Transactions

5

Size

1.81 KB

Version

2

Bits

0a6cb972

Nonce

12,830

Timestamp

1/25/2014, 8:30:41 PM

Confirmations

6,437,316

Merkle Root

ccf3c7332dcab732fb0298f403798aa20a13fdc49fcc60741092d604ddc33285
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.

1.218 × 10¹⁰²(103-digit number)
12182045625291933421…23944764786762385919
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
1.218 × 10¹⁰²(103-digit number)
12182045625291933421…23944764786762385919
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
2.436 × 10¹⁰²(103-digit number)
24364091250583866842…47889529573524771839
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
4.872 × 10¹⁰²(103-digit number)
48728182501167733684…95779059147049543679
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
9.745 × 10¹⁰²(103-digit number)
97456365002335467369…91558118294099087359
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
1.949 × 10¹⁰³(104-digit number)
19491273000467093473…83116236588198174719
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
3.898 × 10¹⁰³(104-digit number)
38982546000934186947…66232473176396349439
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
7.796 × 10¹⁰³(104-digit number)
77965092001868373895…32464946352792698879
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
1.559 × 10¹⁰⁴(105-digit number)
15593018400373674779…64929892705585397759
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
3.118 × 10¹⁰⁴(105-digit number)
31186036800747349558…29859785411170795519
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
6.237 × 10¹⁰⁴(105-digit number)
62372073601494699116…59719570822341591039
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:57,747,640 XPM·at block #6,812,949 · updates every 60s
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