Block #2,846,062

2CCLength 11★★★☆☆

Cunningham Chain of the Second Kind · Discovered 9/19/2018, 8:12:53 AM · Difficulty 11.7301 · 3,992,563 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
d0aa955b93c16e171564f18f48d94bdbbc20a1d0a180ba193a0b65d79872fad7

Height

#2,846,062

Difficulty

11.730092

Transactions

2

Size

869 B

Version

2

Bits

0bbae74f

Nonce

1,139,236,301

Timestamp

9/19/2018, 8:12:53 AM

Confirmations

3,992,563

Merkle Root

c4c009a6215c77148eb8036d2b67f455abfecf35d11bd7a8b2f0fcfa3601c261
Transactions (2)
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.

4.734 × 10⁹⁴(95-digit number)
47343106470812734831…59142186164202403321
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
4.734 × 10⁹⁴(95-digit number)
47343106470812734831…59142186164202403321
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
9.468 × 10⁹⁴(95-digit number)
94686212941625469663…18284372328404806641
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
1.893 × 10⁹⁵(96-digit number)
18937242588325093932…36568744656809613281
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
3.787 × 10⁹⁵(96-digit number)
37874485176650187865…73137489313619226561
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
7.574 × 10⁹⁵(96-digit number)
75748970353300375730…46274978627238453121
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
1.514 × 10⁹⁶(97-digit number)
15149794070660075146…92549957254476906241
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
3.029 × 10⁹⁶(97-digit number)
30299588141320150292…85099914508953812481
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
6.059 × 10⁹⁶(97-digit number)
60599176282640300584…70199829017907624961
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
1.211 × 10⁹⁷(98-digit number)
12119835256528060116…40399658035815249921
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
2.423 × 10⁹⁷(98-digit number)
24239670513056120233…80799316071630499841
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
11
2^10 × origin + 1
4.847 × 10⁹⁷(98-digit number)
48479341026112240467…61598632143260999681
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 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
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 2CC formula:

2CC: p₁ (first prime), p₂ = 2p₁ − 1, p₃ = 2p₂ − 1, …
Circulating Supply:57,953,261 XPM·at block #6,838,624 · updates every 60s
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