Block #2,806,833

1CCLength 11★★★☆☆

Cunningham Chain of the First Kind · Discovered 8/23/2018, 6:35:19 PM · Difficulty 11.6712 · 4,035,083 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
4cbb05db60fe06f1c0506d865b1b43bf7d2afe3e298564b73affe1431203171a

Height

#2,806,833

Difficulty

11.671236

Transactions

18

Size

6.47 KB

Version

2

Bits

0babd627

Nonce

499,504,342

Timestamp

8/23/2018, 6:35:19 PM

Confirmations

4,035,083

Merkle Root

f9d4cc942231cf69dbd448a02158a1ffc13ea78e915b36837b4fe334a0824093
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.

7.293 × 10⁹⁶(97-digit number)
72930567637070488925…43733482724672831999
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
7.293 × 10⁹⁶(97-digit number)
72930567637070488925…43733482724672831999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
1.458 × 10⁹⁷(98-digit number)
14586113527414097785…87466965449345663999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
2.917 × 10⁹⁷(98-digit number)
29172227054828195570…74933930898691327999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
5.834 × 10⁹⁷(98-digit number)
58344454109656391140…49867861797382655999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
1.166 × 10⁹⁸(99-digit number)
11668890821931278228…99735723594765311999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
2.333 × 10⁹⁸(99-digit number)
23337781643862556456…99471447189530623999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
4.667 × 10⁹⁸(99-digit number)
46675563287725112912…98942894379061247999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
9.335 × 10⁹⁸(99-digit number)
93351126575450225824…97885788758122495999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
1.867 × 10⁹⁹(100-digit number)
18670225315090045164…95771577516244991999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
3.734 × 10⁹⁹(100-digit number)
37340450630180090329…91543155032489983999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
11
2^10 × origin − 1
7.468 × 10⁹⁹(100-digit number)
74680901260360180659…83086310064979967999
Verify on FactorDB ↗Wolfram Alpha ↗

What this block proved

The miner who found this block proved the existence of 11 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
RareChain length 11

Approximately 1 in 1,000 blocks. Noteworthy discoveries.

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:57,979,703 XPM·at block #6,841,915 · updates every 60s
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