Block #480,749

TWNLength 10★★☆☆☆

Bi-Twin Chain · Discovered 4/8/2014, 11:49:17 AM · Difficulty 10.5226 · 6,312,675 confirmations

TWN
Bi-Twin Chain

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

Block Header
Block Hash
1522a72f8dcce3762fc0102c792b16b7c4588fe3df9238c28c40091e80eb9fde

Height

#480,749

Difficulty

10.522626

Transactions

9

Size

2.54 KB

Version

2

Bits

0a85cad6

Nonce

324,274,715

Timestamp

4/8/2014, 11:49:17 AM

Confirmations

6,312,675

Merkle Root

ba3a10cd3a6fb9609a6dee99fd594d2d96bc2fb4114b1e622e1da046c10460c0
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.

7.388 × 10⁹⁸(99-digit number)
73889813339932153579…66515480527876492799
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
7.388 × 10⁹⁸(99-digit number)
73889813339932153579…66515480527876492799
Verify on FactorDB ↗Wolfram Alpha ↗
origin + 1
7.388 × 10⁹⁸(99-digit number)
73889813339932153579…66515480527876492801
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
1.477 × 10⁹⁹(100-digit number)
14777962667986430715…33030961055752985599
Verify on FactorDB ↗Wolfram Alpha ↗
2^1 × origin + 1
1.477 × 10⁹⁹(100-digit number)
14777962667986430715…33030961055752985601
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
2.955 × 10⁹⁹(100-digit number)
29555925335972861431…66061922111505971199
Verify on FactorDB ↗Wolfram Alpha ↗
2^2 × origin + 1
2.955 × 10⁹⁹(100-digit number)
29555925335972861431…66061922111505971201
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
5.911 × 10⁹⁹(100-digit number)
59111850671945722863…32123844223011942399
Verify on FactorDB ↗Wolfram Alpha ↗
2^3 × origin + 1
5.911 × 10⁹⁹(100-digit number)
59111850671945722863…32123844223011942401
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
1.182 × 10¹⁰⁰(101-digit number)
11822370134389144572…64247688446023884799
Verify on FactorDB ↗Wolfram Alpha ↗
2^4 × origin + 1
1.182 × 10¹⁰⁰(101-digit number)
11822370134389144572…64247688446023884801
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:57,591,376 XPM·at block #6,793,423 · updates every 60s
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