Block #920,088

TWNLength 10★★☆☆☆

Bi-Twin Chain · Discovered 2/2/2015, 5:22:30 PM · Difficulty 10.9184 · 5,873,211 confirmations

TWN
Bi-Twin Chain

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

Block Header
Block Hash
3080f506d669cf522bc8f1131a46a0bfa59bfdfa9378eb2d535ac18dfaff34e7

Height

#920,088

Difficulty

10.918430

Transactions

5

Size

37.34 KB

Version

2

Bits

0aeb1e35

Nonce

389,040,937

Timestamp

2/2/2015, 5:22:30 PM

Confirmations

5,873,211

Merkle Root

ea545cd22a47999b6d4276cf1d96e88bef93fd98324dc003b22bee74bba3daef
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.

1.938 × 10⁹⁶(97-digit number)
19380512554091620258…74775748603813651199
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
1.938 × 10⁹⁶(97-digit number)
19380512554091620258…74775748603813651199
Verify on FactorDB ↗Wolfram Alpha ↗
origin + 1
1.938 × 10⁹⁶(97-digit number)
19380512554091620258…74775748603813651201
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
3.876 × 10⁹⁶(97-digit number)
38761025108183240517…49551497207627302399
Verify on FactorDB ↗Wolfram Alpha ↗
2^1 × origin + 1
3.876 × 10⁹⁶(97-digit number)
38761025108183240517…49551497207627302401
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
7.752 × 10⁹⁶(97-digit number)
77522050216366481035…99102994415254604799
Verify on FactorDB ↗Wolfram Alpha ↗
2^2 × origin + 1
7.752 × 10⁹⁶(97-digit number)
77522050216366481035…99102994415254604801
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
1.550 × 10⁹⁷(98-digit number)
15504410043273296207…98205988830509209599
Verify on FactorDB ↗Wolfram Alpha ↗
2^3 × origin + 1
1.550 × 10⁹⁷(98-digit number)
15504410043273296207…98205988830509209601
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
3.100 × 10⁹⁷(98-digit number)
31008820086546592414…96411977661018419199
Verify on FactorDB ↗Wolfram Alpha ↗
2^4 × origin + 1
3.100 × 10⁹⁷(98-digit number)
31008820086546592414…96411977661018419201
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:57,590,392 XPM·at block #6,793,298 · updates every 60s
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