Block #922,448

TWNLength 10★★☆☆☆

Bi-Twin Chain · Discovered 2/4/2015, 11:54:12 AM · Difficulty 10.9153 · 5,880,688 confirmations

TWN
Bi-Twin Chain

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

Block Header
Block Hash
65ad89f38a41eec3183dc8e16c3fb40d3543ac758a6ec2d34ae4be99651e8764

Height

#922,448

Difficulty

10.915322

Transactions

5

Size

116.03 KB

Version

2

Bits

0aea528b

Nonce

77,883,978

Timestamp

2/4/2015, 11:54:12 AM

Confirmations

5,880,688

Merkle Root

1d0584681843898fba008752c5042e98c64a57b7f07736af671b04ca09d88c3c
Transactions (5)
1 in → 1 out9.5800 XPM116 B
200 in → 1 out1019.9753 XPM28.96 KB
200 in → 1 out978.6033 XPM28.96 KB
200 in → 1 out1035.6497 XPM28.96 KB
200 in → 1 out1000.5261 XPM28.96 KB
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.

1.313 × 10⁹⁸(99-digit number)
13131807781539049707…18418344031567871999
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
1.313 × 10⁹⁸(99-digit number)
13131807781539049707…18418344031567871999
Verify on FactorDB ↗Wolfram Alpha ↗
origin + 1
1.313 × 10⁹⁸(99-digit number)
13131807781539049707…18418344031567872001
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
2.626 × 10⁹⁸(99-digit number)
26263615563078099415…36836688063135743999
Verify on FactorDB ↗Wolfram Alpha ↗
2^1 × origin + 1
2.626 × 10⁹⁸(99-digit number)
26263615563078099415…36836688063135744001
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
5.252 × 10⁹⁸(99-digit number)
52527231126156198831…73673376126271487999
Verify on FactorDB ↗Wolfram Alpha ↗
2^2 × origin + 1
5.252 × 10⁹⁸(99-digit number)
52527231126156198831…73673376126271488001
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
1.050 × 10⁹⁹(100-digit number)
10505446225231239766…47346752252542975999
Verify on FactorDB ↗Wolfram Alpha ↗
2^3 × origin + 1
1.050 × 10⁹⁹(100-digit number)
10505446225231239766…47346752252542976001
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
2.101 × 10⁹⁹(100-digit number)
21010892450462479532…94693504505085951999
Verify on FactorDB ↗Wolfram Alpha ↗
2^4 × origin + 1
2.101 × 10⁹⁹(100-digit number)
21010892450462479532…94693504505085952001
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:57,669,119 XPM·at block #6,803,135 · updates every 60s
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