Block #473,979

TWNLength 10★★☆☆☆

Bi-Twin Chain · Discovered 4/4/2014, 7:05:14 AM · Difficulty 10.4462 · 6,322,671 confirmations

TWN
Bi-Twin Chain

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

Block Header
Block Hash
0312b4c62d66821941f6330fb040b2e51849367eff054cf451fdbcf2cf06f6e4

Height

#473,979

Difficulty

10.446217

Transactions

3

Size

1.07 KB

Version

2

Bits

0a723b3f

Nonce

77,522

Timestamp

4/4/2014, 7:05:14 AM

Confirmations

6,322,671

Merkle Root

4380a7c9bec1342ec61ceedb15adf0a2e0d8c02937d5b5677896a1b3c941d8e8
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.

1.346 × 10⁹⁶(97-digit number)
13464129836972202902…91853564606044635519
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
1.346 × 10⁹⁶(97-digit number)
13464129836972202902…91853564606044635519
Verify on FactorDB ↗Wolfram Alpha ↗
origin + 1
1.346 × 10⁹⁶(97-digit number)
13464129836972202902…91853564606044635521
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
2.692 × 10⁹⁶(97-digit number)
26928259673944405804…83707129212089271039
Verify on FactorDB ↗Wolfram Alpha ↗
2^1 × origin + 1
2.692 × 10⁹⁶(97-digit number)
26928259673944405804…83707129212089271041
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
5.385 × 10⁹⁶(97-digit number)
53856519347888811608…67414258424178542079
Verify on FactorDB ↗Wolfram Alpha ↗
2^2 × origin + 1
5.385 × 10⁹⁶(97-digit number)
53856519347888811608…67414258424178542081
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
1.077 × 10⁹⁷(98-digit number)
10771303869577762321…34828516848357084159
Verify on FactorDB ↗Wolfram Alpha ↗
2^3 × origin + 1
1.077 × 10⁹⁷(98-digit number)
10771303869577762321…34828516848357084161
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
2.154 × 10⁹⁷(98-digit number)
21542607739155524643…69657033696714168319
Verify on FactorDB ↗Wolfram Alpha ↗
2^4 × origin + 1
2.154 × 10⁹⁷(98-digit number)
21542607739155524643…69657033696714168321
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:57,617,203 XPM·at block #6,796,649 · updates every 60s
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