Block #414,496

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 2/22/2014, 1:34:14 AM · Difficulty 10.4019 · 6,377,968 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
768f774b19839cd1b87499f79b9de78e955b2a83c84f25433b11b1138c0f177f

Height

#414,496

Difficulty

10.401904

Transactions

9

Size

2.25 KB

Version

2

Bits

0a66e331

Nonce

476,633

Timestamp

2/22/2014, 1:34:14 AM

Confirmations

6,377,968

Merkle Root

a93d78a6b7ac1d529df4c6c8c06370b1fbab0b2ae7ae244e8f9a2768ccb54da6
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.

4.989 × 10⁹⁵(96-digit number)
49893008943223953183…24557411955699020001
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
4.989 × 10⁹⁵(96-digit number)
49893008943223953183…24557411955699020001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
9.978 × 10⁹⁵(96-digit number)
99786017886447906367…49114823911398040001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
1.995 × 10⁹⁶(97-digit number)
19957203577289581273…98229647822796080001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
3.991 × 10⁹⁶(97-digit number)
39914407154579162546…96459295645592160001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
7.982 × 10⁹⁶(97-digit number)
79828814309158325093…92918591291184320001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
1.596 × 10⁹⁷(98-digit number)
15965762861831665018…85837182582368640001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
3.193 × 10⁹⁷(98-digit number)
31931525723663330037…71674365164737280001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
6.386 × 10⁹⁷(98-digit number)
63863051447326660074…43348730329474560001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
1.277 × 10⁹⁸(99-digit number)
12772610289465332014…86697460658949120001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
2.554 × 10⁹⁸(99-digit number)
25545220578930664029…73394921317898240001
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 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
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 2CC formula:

2CC: p₁ (first prime), p₂ = 2p₁ − 1, p₃ = 2p₂ − 1, …
Circulating Supply:57,583,673 XPM·at block #6,792,463 · updates every 60s
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