Block #404,447

TWNLength 10★★☆☆☆

Bi-Twin Chain · Discovered 2/14/2014, 8:34:12 PM · Difficulty 10.4353 · 6,393,368 confirmations

TWN
Bi-Twin Chain

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

Block Header
Block Hash
2a8322492d68b0589a7f76e90f2adfee368d148fae74c23d86c2a382d104f744

Height

#404,447

Difficulty

10.435342

Transactions

11

Size

2.84 KB

Version

2

Bits

0a6f7293

Nonce

127,035

Timestamp

2/14/2014, 8:34:12 PM

Confirmations

6,393,368

Merkle Root

c449e5a285f382fab141f3b87bf85a5f78e4096965b7f20decab13a5cc16be8d
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.

6.000 × 10¹⁰²(103-digit number)
60001224590857029526…22809130460361175519
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
6.000 × 10¹⁰²(103-digit number)
60001224590857029526…22809130460361175519
Verify on FactorDB ↗Wolfram Alpha ↗
origin + 1
6.000 × 10¹⁰²(103-digit number)
60001224590857029526…22809130460361175521
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
1.200 × 10¹⁰³(104-digit number)
12000244918171405905…45618260920722351039
Verify on FactorDB ↗Wolfram Alpha ↗
2^1 × origin + 1
1.200 × 10¹⁰³(104-digit number)
12000244918171405905…45618260920722351041
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
2.400 × 10¹⁰³(104-digit number)
24000489836342811810…91236521841444702079
Verify on FactorDB ↗Wolfram Alpha ↗
2^2 × origin + 1
2.400 × 10¹⁰³(104-digit number)
24000489836342811810…91236521841444702081
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
4.800 × 10¹⁰³(104-digit number)
48000979672685623621…82473043682889404159
Verify on FactorDB ↗Wolfram Alpha ↗
2^3 × origin + 1
4.800 × 10¹⁰³(104-digit number)
48000979672685623621…82473043682889404161
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
9.600 × 10¹⁰³(104-digit number)
96001959345371247242…64946087365778808319
Verify on FactorDB ↗Wolfram Alpha ↗
2^4 × origin + 1
9.600 × 10¹⁰³(104-digit number)
96001959345371247242…64946087365778808321
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:57,626,499 XPM·at block #6,797,814 · updates every 60s
xpmprime.info is a work in progress. If you enjoy using this service you can support this project with a Primecoin donation.