Block #3,494,215

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 12/30/2019, 4:28:08 PM · Difficulty 10.9497 · 3,349,787 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
98432c106235a54ead3f66720454dca69a42ef9bace7b4a0c9e9c8adb6f04876

Height

#3,494,215

Difficulty

10.949742

Transactions

4

Size

995 B

Version

2

Bits

0af32247

Nonce

314,437,166

Timestamp

12/30/2019, 4:28:08 PM

Confirmations

3,349,787

Merkle Root

95a23f22d5a8db941ce514d3dc1fe7ed03df1adbfe1c3edd199d511cc58f8c86
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.

2.561 × 10⁹⁶(97-digit number)
25612278662950028992…62636191880510796799
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
2.561 × 10⁹⁶(97-digit number)
25612278662950028992…62636191880510796799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
5.122 × 10⁹⁶(97-digit number)
51224557325900057984…25272383761021593599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
1.024 × 10⁹⁷(98-digit number)
10244911465180011596…50544767522043187199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
2.048 × 10⁹⁷(98-digit number)
20489822930360023193…01089535044086374399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
4.097 × 10⁹⁷(98-digit number)
40979645860720046387…02179070088172748799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
8.195 × 10⁹⁷(98-digit number)
81959291721440092774…04358140176345497599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
1.639 × 10⁹⁸(99-digit number)
16391858344288018554…08716280352690995199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
3.278 × 10⁹⁸(99-digit number)
32783716688576037109…17432560705381990399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
6.556 × 10⁹⁸(99-digit number)
65567433377152074219…34865121410763980799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
1.311 × 10⁹⁹(100-digit number)
13113486675430414843…69730242821527961599
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:57,996,396 XPM·at block #6,844,001 · updates every 60s
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