Block #308,982

TWNLength 10★★☆☆☆

Bi-Twin Chain · Discovered 12/13/2013, 9:15:44 AM · Difficulty 9.9947 · 6,483,546 confirmations

TWN
Bi-Twin Chain

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

Block Header
Block Hash
8bd9268c804969113129a13f093cf2e99091c35203e8f2976f308481716f1560

Height

#308,982

Difficulty

9.994681

Transactions

12

Size

3.31 KB

Version

2

Bits

09fea363

Nonce

163,904

Timestamp

12/13/2013, 9:15:44 AM

Confirmations

6,483,546

Merkle Root

65da4f17e9a91b750e5a08d10b0fc93fb4055beda3c80e8ece62a96014345c7d
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.

5.859 × 10⁹⁷(98-digit number)
58593029596437543608…30057591111416667199
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
5.859 × 10⁹⁷(98-digit number)
58593029596437543608…30057591111416667199
Verify on FactorDB ↗Wolfram Alpha ↗
origin + 1
5.859 × 10⁹⁷(98-digit number)
58593029596437543608…30057591111416667201
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
1.171 × 10⁹⁸(99-digit number)
11718605919287508721…60115182222833334399
Verify on FactorDB ↗Wolfram Alpha ↗
2^1 × origin + 1
1.171 × 10⁹⁸(99-digit number)
11718605919287508721…60115182222833334401
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
2.343 × 10⁹⁸(99-digit number)
23437211838575017443…20230364445666668799
Verify on FactorDB ↗Wolfram Alpha ↗
2^2 × origin + 1
2.343 × 10⁹⁸(99-digit number)
23437211838575017443…20230364445666668801
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
4.687 × 10⁹⁸(99-digit number)
46874423677150034886…40460728891333337599
Verify on FactorDB ↗Wolfram Alpha ↗
2^3 × origin + 1
4.687 × 10⁹⁸(99-digit number)
46874423677150034886…40460728891333337601
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
9.374 × 10⁹⁸(99-digit number)
93748847354300069773…80921457782666675199
Verify on FactorDB ↗Wolfram Alpha ↗
2^4 × origin + 1
9.374 × 10⁹⁸(99-digit number)
93748847354300069773…80921457782666675201
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:57,584,192 XPM·at block #6,792,527 · updates every 60s
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