1. #6,796,4842CC10 primes

    Cunningham 2nd · ⛏️ coinsforall.io

Block #897,533

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 1/16/2015, 2:55:54 PM · Difficulty 10.9454 · 5,898,952 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
60369348260ff202a52cae156dc488b560e189e0cf643af72518e3f7c03dcd70

Height

#897,533

Difficulty

10.945353

Transactions

9

Size

2.11 KB

Version

2

Bits

0af202a8

Nonce

4,506,913

Timestamp

1/16/2015, 2:55:54 PM

Confirmations

5,898,952

Merkle Root

6606973ced44003f5663682074b09e60c4c4424620ba0701e9375fd9ec5e918d
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.

1.055 × 10⁹⁶(97-digit number)
10553855515799641611…02701873013185856319
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
1.055 × 10⁹⁶(97-digit number)
10553855515799641611…02701873013185856319
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
2.110 × 10⁹⁶(97-digit number)
21107711031599283222…05403746026371712639
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
4.221 × 10⁹⁶(97-digit number)
42215422063198566445…10807492052743425279
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
8.443 × 10⁹⁶(97-digit number)
84430844126397132891…21614984105486850559
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
1.688 × 10⁹⁷(98-digit number)
16886168825279426578…43229968210973701119
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
3.377 × 10⁹⁷(98-digit number)
33772337650558853156…86459936421947402239
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
6.754 × 10⁹⁷(98-digit number)
67544675301117706312…72919872843894804479
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
1.350 × 10⁹⁸(99-digit number)
13508935060223541262…45839745687789608959
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
2.701 × 10⁹⁸(99-digit number)
27017870120447082525…91679491375579217919
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
5.403 × 10⁹⁸(99-digit number)
54035740240894165050…83358982751158435839
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:57,615,878 XPM·at block #6,796,484 · updates every 60s
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