Block #483,955

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 4/10/2014, 7:49:57 AM · Difficulty 10.5746 · 6,319,420 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
b11f0a7e5fbca074d66ce1700fb1a577ee0f9ffc97f8be4450a6920d21458df3

Height

#483,955

Difficulty

10.574635

Transactions

9

Size

1.97 KB

Version

2

Bits

0a931b46

Nonce

47,199,258

Timestamp

4/10/2014, 7:49:57 AM

Confirmations

6,319,420

Merkle Root

f832071ccebffbf4aac11db605b41e1a56e6795476cd424d48abd88ae875f4c4
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.

1.749 × 10⁹⁹(100-digit number)
17499400119427313608…18101996084259386881
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
1.749 × 10⁹⁹(100-digit number)
17499400119427313608…18101996084259386881
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
3.499 × 10⁹⁹(100-digit number)
34998800238854627217…36203992168518773761
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
6.999 × 10⁹⁹(100-digit number)
69997600477709254434…72407984337037547521
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
1.399 × 10¹⁰⁰(101-digit number)
13999520095541850886…44815968674075095041
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
2.799 × 10¹⁰⁰(101-digit number)
27999040191083701773…89631937348150190081
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
5.599 × 10¹⁰⁰(101-digit number)
55998080382167403547…79263874696300380161
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
1.119 × 10¹⁰¹(102-digit number)
11199616076433480709…58527749392600760321
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
2.239 × 10¹⁰¹(102-digit number)
22399232152866961418…17055498785201520641
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
4.479 × 10¹⁰¹(102-digit number)
44798464305733922837…34110997570403041281
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
8.959 × 10¹⁰¹(102-digit number)
89596928611467845675…68221995140806082561
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 Second 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 2CC formula:

2CC: p₁ (first prime), p₂ = 2p₁ − 1, p₃ = 2p₂ − 1, …
Circulating Supply:57,671,036 XPM·at block #6,803,374 · updates every 60s
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