Block #319,085

TWNLength 10★★☆☆☆

Bi-Twin Chain · Discovered 12/18/2013, 7:17:20 PM · Difficulty 10.1642 · 6,482,369 confirmations

TWN
Bi-Twin Chain

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

Block Header
Block Hash
aa2a1752e0c6a7d89d06a6d5df4a10b851302459337b434836373e5b2c033c4f

Height

#319,085

Difficulty

10.164196

Transactions

16

Size

5.92 KB

Version

2

Bits

0a2a08bf

Nonce

509,144

Timestamp

12/18/2013, 7:17:20 PM

Confirmations

6,482,369

Merkle Root

81f98b318e83faca31eb6c3a8525737a606372805058c7b3185d4545fa2aac05
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.

4.834 × 10¹⁰⁰(101-digit number)
48346236213354282113…07192258552086523199
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
4.834 × 10¹⁰⁰(101-digit number)
48346236213354282113…07192258552086523199
Verify on FactorDB ↗Wolfram Alpha ↗
origin + 1
4.834 × 10¹⁰⁰(101-digit number)
48346236213354282113…07192258552086523201
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
9.669 × 10¹⁰⁰(101-digit number)
96692472426708564226…14384517104173046399
Verify on FactorDB ↗Wolfram Alpha ↗
2^1 × origin + 1
9.669 × 10¹⁰⁰(101-digit number)
96692472426708564226…14384517104173046401
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
1.933 × 10¹⁰¹(102-digit number)
19338494485341712845…28769034208346092799
Verify on FactorDB ↗Wolfram Alpha ↗
2^2 × origin + 1
1.933 × 10¹⁰¹(102-digit number)
19338494485341712845…28769034208346092801
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
3.867 × 10¹⁰¹(102-digit number)
38676988970683425690…57538068416692185599
Verify on FactorDB ↗Wolfram Alpha ↗
2^3 × origin + 1
3.867 × 10¹⁰¹(102-digit number)
38676988970683425690…57538068416692185601
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
7.735 × 10¹⁰¹(102-digit number)
77353977941366851381…15076136833384371199
Verify on FactorDB ↗Wolfram Alpha ↗
2^4 × origin + 1
7.735 × 10¹⁰¹(102-digit number)
77353977941366851381…15076136833384371201
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:57,655,705 XPM·at block #6,801,453 · updates every 60s
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