Block #500,718

TWNLength 10★★☆☆☆

Bi-Twin Chain · Discovered 4/19/2014, 8:02:58 AM · Difficulty 10.8016 · 6,295,035 confirmations

TWN
Bi-Twin Chain

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

Block Header
Block Hash
a54e50b524f6ef7b0b5a040c13dc6536978ad0f6ab6ab3ed346c2facf8191d71

Height

#500,718

Difficulty

10.801564

Transactions

10

Size

223.70 KB

Version

2

Bits

0acd3353

Nonce

42,555,669

Timestamp

4/19/2014, 8:02:58 AM

Confirmations

6,295,035

Merkle Root

0422601958ed79645f75f163ee324e82dcf64e6d6cc18a1948ecbeff3c6d7899
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.

1.141 × 10⁹⁵(96-digit number)
11419882677327161746…64811617324442074319
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
1.141 × 10⁹⁵(96-digit number)
11419882677327161746…64811617324442074319
Verify on FactorDB ↗Wolfram Alpha ↗
origin + 1
1.141 × 10⁹⁵(96-digit number)
11419882677327161746…64811617324442074321
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
2.283 × 10⁹⁵(96-digit number)
22839765354654323493…29623234648884148639
Verify on FactorDB ↗Wolfram Alpha ↗
2^1 × origin + 1
2.283 × 10⁹⁵(96-digit number)
22839765354654323493…29623234648884148641
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
4.567 × 10⁹⁵(96-digit number)
45679530709308646987…59246469297768297279
Verify on FactorDB ↗Wolfram Alpha ↗
2^2 × origin + 1
4.567 × 10⁹⁵(96-digit number)
45679530709308646987…59246469297768297281
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
9.135 × 10⁹⁵(96-digit number)
91359061418617293975…18492938595536594559
Verify on FactorDB ↗Wolfram Alpha ↗
2^3 × origin + 1
9.135 × 10⁹⁵(96-digit number)
91359061418617293975…18492938595536594561
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
1.827 × 10⁹⁶(97-digit number)
18271812283723458795…36985877191073189119
Verify on FactorDB ↗Wolfram Alpha ↗
2^4 × origin + 1
1.827 × 10⁹⁶(97-digit number)
18271812283723458795…36985877191073189121
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:57,610,103 XPM·at block #6,795,752 · updates every 60s
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