Block #759,706

2CCLength 11★★★☆☆

Cunningham Chain of the Second Kind · Discovered 10/10/2014, 3:05:36 AM · Difficulty 10.9711 · 6,035,144 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
c3401a1bda0e2db856b3f9fa10f5c76d551e3b7cc998abbd05bbea1b40a6e7cd

Height

#759,706

Difficulty

10.971055

Transactions

2

Size

432 B

Version

2

Bits

0af89716

Nonce

730,527,129

Timestamp

10/10/2014, 3:05:36 AM

Confirmations

6,035,144

Merkle Root

a9c9f6369c841082feecd3daabac9900de227c11b80f18968e52f688d7673f67
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.

2.622 × 10⁹⁶(97-digit number)
26225459308482476680…92066773524356762881
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
2.622 × 10⁹⁶(97-digit number)
26225459308482476680…92066773524356762881
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
5.245 × 10⁹⁶(97-digit number)
52450918616964953360…84133547048713525761
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
1.049 × 10⁹⁷(98-digit number)
10490183723392990672…68267094097427051521
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
2.098 × 10⁹⁷(98-digit number)
20980367446785981344…36534188194854103041
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
4.196 × 10⁹⁷(98-digit number)
41960734893571962688…73068376389708206081
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
8.392 × 10⁹⁷(98-digit number)
83921469787143925376…46136752779416412161
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
1.678 × 10⁹⁸(99-digit number)
16784293957428785075…92273505558832824321
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
3.356 × 10⁹⁸(99-digit number)
33568587914857570150…84547011117665648641
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
6.713 × 10⁹⁸(99-digit number)
67137175829715140301…69094022235331297281
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
1.342 × 10⁹⁹(100-digit number)
13427435165943028060…38188044470662594561
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
11
2^10 × origin + 1
2.685 × 10⁹⁹(100-digit number)
26854870331886056120…76376088941325189121
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:57,602,829 XPM·at block #6,794,849 · updates every 60s
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