Block #522,215

TWNLength 10★★☆☆☆

Bi-Twin Chain · Discovered 5/2/2014, 10:06:15 PM · Difficulty 10.8659 · 6,273,425 confirmations

TWN
Bi-Twin Chain

Interleaved pairs of primes that differ by 2, forming twin prime pairs at each level.

Block Header
Block Hash
bcd281c5d24bee55f86ff624ae71fc2c6b4ed47135eb9dd9f879b5f04a2d9f8b

Height

#522,215

Difficulty

10.865948

Transactions

6

Size

1.74 KB

Version

2

Bits

0addaec1

Nonce

6,892,709

Timestamp

5/2/2014, 10:06:15 PM

Confirmations

6,273,425

Merkle Root

ad5056f30820d03aee59816030f6261a65ea0d79b1b8dcecbaf58d08a856603c
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.

1.176 × 10⁹⁹(100-digit number)
11769984607092415214…79778679615822769599
Discovered Prime Numbers
Lower: 2^k × origin − 1 | Upper: 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.

Level 0 — Twin Prime Pair (origin ± 1)
origin − 1
1.176 × 10⁹⁹(100-digit number)
11769984607092415214…79778679615822769599
Verify on FactorDB ↗Wolfram Alpha ↗
origin + 1
1.176 × 10⁹⁹(100-digit number)
11769984607092415214…79778679615822769601
Verify on FactorDB ↗Wolfram Alpha ↗
Difference: origin + 1 − origin − 1 = 2 (twin primes ✓)
Level 1 — Twin Prime Pair (2^1 × origin ± 1)
2^1 × origin − 1
2.353 × 10⁹⁹(100-digit number)
23539969214184830428…59557359231645539199
Verify on FactorDB ↗Wolfram Alpha ↗
2^1 × origin + 1
2.353 × 10⁹⁹(100-digit number)
23539969214184830428…59557359231645539201
Verify on FactorDB ↗Wolfram Alpha ↗
Difference: 2^1 × origin + 1 − 2^1 × origin − 1 = 2 (twin primes ✓)
Level 2 — Twin Prime Pair (2^2 × origin ± 1)
2^2 × origin − 1
4.707 × 10⁹⁹(100-digit number)
47079938428369660856…19114718463291078399
Verify on FactorDB ↗Wolfram Alpha ↗
2^2 × origin + 1
4.707 × 10⁹⁹(100-digit number)
47079938428369660856…19114718463291078401
Verify on FactorDB ↗Wolfram Alpha ↗
Difference: 2^2 × origin + 1 − 2^2 × origin − 1 = 2 (twin primes ✓)
Level 3 — Twin Prime Pair (2^3 × origin ± 1)
2^3 × origin − 1
9.415 × 10⁹⁹(100-digit number)
94159876856739321712…38229436926582156799
Verify on FactorDB ↗Wolfram Alpha ↗
2^3 × origin + 1
9.415 × 10⁹⁹(100-digit number)
94159876856739321712…38229436926582156801
Verify on FactorDB ↗Wolfram Alpha ↗
Difference: 2^3 × origin + 1 − 2^3 × origin − 1 = 2 (twin primes ✓)
Level 4 — Twin Prime Pair (2^4 × origin ± 1)
2^4 × origin − 1
1.883 × 10¹⁰⁰(101-digit number)
18831975371347864342…76458873853164313599
Verify on FactorDB ↗Wolfram Alpha ↗
2^4 × origin + 1
1.883 × 10¹⁰⁰(101-digit number)
18831975371347864342…76458873853164313601
Verify on FactorDB ↗Wolfram Alpha ↗
Difference: 2^4 × origin + 1 − 2^4 × origin − 1 = 2 (twin primes ✓)

What this block proved

The miner who found this block proved the existence of 10 consecutive prime numbers forming a Bi-Twin Chain. 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 TWN formula:

TWN: twin pairs (p, p+2) where p = origin/primorial − 1 and p+2 = origin/primorial + 1
Circulating Supply:57,609,189 XPM·at block #6,795,639 · updates every 60s
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