Block #2,088,481

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 4/26/2017, 9:07:47 AM · Difficulty 10.8754 · 4,721,421 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
447cf4371f096744e2ca99d1553b5c880bb8446d607bdb3cd6535ffb5aa2771b

Height

#2,088,481

Difficulty

10.875398

Transactions

4

Size

2.01 KB

Version

2

Bits

0ae01a1d

Nonce

194,343

Timestamp

4/26/2017, 9:07:47 AM

Confirmations

4,721,421

Merkle Root

cc55fdc94685479ae2897087cd544b8623b7773cfba4381e632db5f77f65f7e0
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.

1.554 × 10¹⁰⁰(101-digit number)
15547507200447073675…38478318473749801359
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
1.554 × 10¹⁰⁰(101-digit number)
15547507200447073675…38478318473749801359
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
3.109 × 10¹⁰⁰(101-digit number)
31095014400894147351…76956636947499602719
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
6.219 × 10¹⁰⁰(101-digit number)
62190028801788294702…53913273894999205439
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
1.243 × 10¹⁰¹(102-digit number)
12438005760357658940…07826547789998410879
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
2.487 × 10¹⁰¹(102-digit number)
24876011520715317880…15653095579996821759
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
4.975 × 10¹⁰¹(102-digit number)
49752023041430635761…31306191159993643519
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
9.950 × 10¹⁰¹(102-digit number)
99504046082861271523…62612382319987287039
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
1.990 × 10¹⁰²(103-digit number)
19900809216572254304…25224764639974574079
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
3.980 × 10¹⁰²(103-digit number)
39801618433144508609…50449529279949148159
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
7.960 × 10¹⁰²(103-digit number)
79603236866289017218…00899058559898296319
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:57,723,298 XPM·at block #6,809,901 · updates every 60s
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