Block #298,460

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 12/7/2013, 8:31:59 AM · Difficulty 9.9919 · 6,492,482 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
c77e25868ec7d7aeea7d5003a9a833652b032471753d0d2cfbc26076795434fa

Height

#298,460

Difficulty

9.991942

Transactions

6

Size

4.59 KB

Version

2

Bits

09fdeff1

Nonce

1,031

Timestamp

12/7/2013, 8:31:59 AM

Confirmations

6,492,482

Merkle Root

77f471fc3a26d6bf1eafc8ae687d2349c2f53c0d90f1ec205b40c941b5c4ac18
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.

6.526 × 10⁹⁵(96-digit number)
65260114698591454760…87458712147030430719
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
6.526 × 10⁹⁵(96-digit number)
65260114698591454760…87458712147030430719
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
1.305 × 10⁹⁶(97-digit number)
13052022939718290952…74917424294060861439
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
2.610 × 10⁹⁶(97-digit number)
26104045879436581904…49834848588121722879
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
5.220 × 10⁹⁶(97-digit number)
52208091758873163808…99669697176243445759
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
1.044 × 10⁹⁷(98-digit number)
10441618351774632761…99339394352486891519
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
2.088 × 10⁹⁷(98-digit number)
20883236703549265523…98678788704973783039
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
4.176 × 10⁹⁷(98-digit number)
41766473407098531046…97357577409947566079
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
8.353 × 10⁹⁷(98-digit number)
83532946814197062093…94715154819895132159
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
1.670 × 10⁹⁸(99-digit number)
16706589362839412418…89430309639790264319
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
3.341 × 10⁹⁸(99-digit number)
33413178725678824837…78860619279580528639
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:57,571,546 XPM·at block #6,790,941 · updates every 60s