Block #3,029,414

2CCLength 12★★★★☆

Cunningham Chain of the Second Kind · Discovered 1/28/2019, 7:46:35 PM · Difficulty 11.1282 · 3,812,006 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
b77cc5cf510599b90350cc6daa3e76e870cd6784efcebe4467c8bdbd1a00dba6

Height

#3,029,414

Difficulty

11.128230

Transactions

4

Size

1.84 KB

Version

2

Bits

0b20d3b5

Nonce

809,914,325

Timestamp

1/28/2019, 7:46:35 PM

Confirmations

3,812,006

Merkle Root

0dda3afb31eb6a197edbb47c4377f43fb857f4a4e838514b303284a60e2f908f
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.

2.990 × 10⁹⁵(96-digit number)
29905771331649059227…09967618676497280641
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
2.990 × 10⁹⁵(96-digit number)
29905771331649059227…09967618676497280641
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
5.981 × 10⁹⁵(96-digit number)
59811542663298118454…19935237352994561281
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
1.196 × 10⁹⁶(97-digit number)
11962308532659623690…39870474705989122561
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
2.392 × 10⁹⁶(97-digit number)
23924617065319247381…79740949411978245121
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
4.784 × 10⁹⁶(97-digit number)
47849234130638494763…59481898823956490241
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
9.569 × 10⁹⁶(97-digit number)
95698468261276989527…18963797647912980481
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
1.913 × 10⁹⁷(98-digit number)
19139693652255397905…37927595295825960961
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
3.827 × 10⁹⁷(98-digit number)
38279387304510795811…75855190591651921921
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
7.655 × 10⁹⁷(98-digit number)
76558774609021591622…51710381183303843841
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
1.531 × 10⁹⁸(99-digit number)
15311754921804318324…03420762366607687681
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
11
2^10 × origin + 1
3.062 × 10⁹⁸(99-digit number)
30623509843608636648…06841524733215375361
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
12
2^11 × origin + 1
6.124 × 10⁹⁸(99-digit number)
61247019687217273297…13683049466430750721
Verify on FactorDB ↗Wolfram Alpha ↗

What this block proved

The miner who found this block proved the existence of 12 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
ExceptionalChain length 12

Around 1 in 10,000 blocks. A significant mathematical achievement.

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:57,975,736 XPM·at block #6,841,419 · updates every 60s
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