Block #164,792

TWNLength 10★★☆☆☆

Bi-Twin Chain · Discovered 9/14/2013, 9:31:10 PM · Difficulty 9.8637 · 6,638,547 confirmations

TWN
Bi-Twin Chain

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

Block Header
Block Hash
f1a620468e84c81e9304b3261d1378c5874be7c28a695068f3086e1651438d01

Height

#164,792

Difficulty

9.863681

Transactions

17

Size

5.17 KB

Version

2

Bits

09dd1a31

Nonce

21,522

Timestamp

9/14/2013, 9:31:10 PM

Confirmations

6,638,547

Merkle Root

cff0558d34232f84a499382c848221e54bebcdf993f2ea7b81149e38f46164f7
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.

4.303 × 10⁹¹(92-digit number)
43037626322883148480…88233701951354147039
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
4.303 × 10⁹¹(92-digit number)
43037626322883148480…88233701951354147039
Verify on FactorDB ↗Wolfram Alpha ↗
origin + 1
4.303 × 10⁹¹(92-digit number)
43037626322883148480…88233701951354147041
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
8.607 × 10⁹¹(92-digit number)
86075252645766296961…76467403902708294079
Verify on FactorDB ↗Wolfram Alpha ↗
2^1 × origin + 1
8.607 × 10⁹¹(92-digit number)
86075252645766296961…76467403902708294081
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
1.721 × 10⁹²(93-digit number)
17215050529153259392…52934807805416588159
Verify on FactorDB ↗Wolfram Alpha ↗
2^2 × origin + 1
1.721 × 10⁹²(93-digit number)
17215050529153259392…52934807805416588161
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
3.443 × 10⁹²(93-digit number)
34430101058306518784…05869615610833176319
Verify on FactorDB ↗Wolfram Alpha ↗
2^3 × origin + 1
3.443 × 10⁹²(93-digit number)
34430101058306518784…05869615610833176321
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
6.886 × 10⁹²(93-digit number)
68860202116613037568…11739231221666352639
Verify on FactorDB ↗Wolfram Alpha ↗
2^4 × origin + 1
6.886 × 10⁹²(93-digit number)
68860202116613037568…11739231221666352641
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:57,670,744 XPM·at block #6,803,338 · updates every 60s
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