Block #857,549

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 12/17/2014, 10:23:24 PM · Difficulty 10.9675 · 5,985,876 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
05b72678af5f1b8f3854e3bd47aa4f8acf2e14c07b52eb7ec809ac1564b34caf

Height

#857,549

Difficulty

10.967454

Transactions

17

Size

3.80 KB

Version

2

Bits

0af7ab16

Nonce

840,855,959

Timestamp

12/17/2014, 10:23:24 PM

Confirmations

5,985,876

Merkle Root

20c45fbfd2f57117ded88adf22cfdf5dc1303a5e4cce459ed3d08c20237c1bca
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.

4.429 × 10⁹³(94-digit number)
44293878245309568208…27558976777799744059
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
4.429 × 10⁹³(94-digit number)
44293878245309568208…27558976777799744059
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
8.858 × 10⁹³(94-digit number)
88587756490619136417…55117953555599488119
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
1.771 × 10⁹⁴(95-digit number)
17717551298123827283…10235907111198976239
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
3.543 × 10⁹⁴(95-digit number)
35435102596247654566…20471814222397952479
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
7.087 × 10⁹⁴(95-digit number)
70870205192495309133…40943628444795904959
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
1.417 × 10⁹⁵(96-digit number)
14174041038499061826…81887256889591809919
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
2.834 × 10⁹⁵(96-digit number)
28348082076998123653…63774513779183619839
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
5.669 × 10⁹⁵(96-digit number)
56696164153996247307…27549027558367239679
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
1.133 × 10⁹⁶(97-digit number)
11339232830799249461…55098055116734479359
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
2.267 × 10⁹⁶(97-digit number)
22678465661598498922…10196110233468958719
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 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
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 1CC formula:

1CC: p₁ (first prime), p₂ = 2p₁ + 1, p₃ = 2p₂ + 1, …
Circulating Supply:57,991,769 XPM·at block #6,843,424 · updates every 60s
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