Block #294,841

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 12/5/2013, 2:45:45 AM · Difficulty 9.9912 · 6,510,260 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
b60f8712b9531e27698613b5a814f55c86cd69fefed42eb4da0fdf03edaea688

Height

#294,841

Difficulty

9.991168

Transactions

15

Size

4.74 KB

Version

2

Bits

09fdbd32

Nonce

79,397

Timestamp

12/5/2013, 2:45:45 AM

Confirmations

6,510,260

Merkle Root

af89568e231c3a43505fb7c29e5e05fabe7b947f31ca58c6eb899bbece2106b8
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.

1.164 × 10⁹⁴(95-digit number)
11645839290740085829…90750858631641241599
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
1.164 × 10⁹⁴(95-digit number)
11645839290740085829…90750858631641241599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
2.329 × 10⁹⁴(95-digit number)
23291678581480171659…81501717263282483199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
4.658 × 10⁹⁴(95-digit number)
46583357162960343318…63003434526564966399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
9.316 × 10⁹⁴(95-digit number)
93166714325920686636…26006869053129932799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
1.863 × 10⁹⁵(96-digit number)
18633342865184137327…52013738106259865599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
3.726 × 10⁹⁵(96-digit number)
37266685730368274654…04027476212519731199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
7.453 × 10⁹⁵(96-digit number)
74533371460736549309…08054952425039462399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
1.490 × 10⁹⁶(97-digit number)
14906674292147309861…16109904850078924799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
2.981 × 10⁹⁶(97-digit number)
29813348584294619723…32219809700157849599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
5.962 × 10⁹⁶(97-digit number)
59626697168589239447…64439619400315699199
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:57,684,875 XPM·at block #6,805,100 · updates every 60s
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