Block #292,351

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 12/3/2013, 4:46:23 PM · Difficulty 9.9903 · 6,503,603 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
98f380b7aaafdfe193b39a0b0a21553493a4ee01138688ded5fb6b398f6e6d1b

Height

#292,351

Difficulty

9.990255

Transactions

19

Size

12.67 KB

Version

2

Bits

09fd8160

Nonce

727,246

Timestamp

12/3/2013, 4:46:23 PM

Confirmations

6,503,603

Merkle Root

b1ba978d668afbfb960723b1f5bc371d56ea17fad8c8ccd164a12d9b68128b46
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.

3.523 × 10⁹⁵(96-digit number)
35231056226672736048…28452673154067577599
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
3.523 × 10⁹⁵(96-digit number)
35231056226672736048…28452673154067577599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
7.046 × 10⁹⁵(96-digit number)
70462112453345472096…56905346308135155199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
1.409 × 10⁹⁶(97-digit number)
14092422490669094419…13810692616270310399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
2.818 × 10⁹⁶(97-digit number)
28184844981338188838…27621385232540620799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
5.636 × 10⁹⁶(97-digit number)
56369689962676377677…55242770465081241599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
1.127 × 10⁹⁷(98-digit number)
11273937992535275535…10485540930162483199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
2.254 × 10⁹⁷(98-digit number)
22547875985070551070…20971081860324966399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
4.509 × 10⁹⁷(98-digit number)
45095751970141102141…41942163720649932799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
9.019 × 10⁹⁷(98-digit number)
90191503940282204283…83884327441299865599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
1.803 × 10⁹⁸(99-digit number)
18038300788056440856…67768654882599731199
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:57,611,722 XPM·at block #6,795,953 · updates every 60s
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