Block #274,060

TWNLength 10★★☆☆☆

Bi-Twin Chain · Discovered 11/26/2013, 3:17:30 AM · Difficulty 9.9562 · 6,529,736 confirmations

TWN
Bi-Twin Chain

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

Block Header
Block Hash
bc4ef30b86dce6230d0ad94fe7c3bcfc7492930b6f02f69a6d2be84c1d53c503

Height

#274,060

Difficulty

9.956243

Transactions

8

Size

4.92 KB

Version

2

Bits

09f4cc5d

Nonce

28,819

Timestamp

11/26/2013, 3:17:30 AM

Confirmations

6,529,736

Merkle Root

16d6254cc2ab9eebc1d874cef8b255e5d4c7235907800e9d160d8225211d4fee
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.

2.019 × 10⁹⁵(96-digit number)
20197280872846630313…19377621180754872499
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
2.019 × 10⁹⁵(96-digit number)
20197280872846630313…19377621180754872499
Verify on FactorDB ↗Wolfram Alpha ↗
origin + 1
2.019 × 10⁹⁵(96-digit number)
20197280872846630313…19377621180754872501
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
4.039 × 10⁹⁵(96-digit number)
40394561745693260627…38755242361509744999
Verify on FactorDB ↗Wolfram Alpha ↗
2^1 × origin + 1
4.039 × 10⁹⁵(96-digit number)
40394561745693260627…38755242361509745001
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
8.078 × 10⁹⁵(96-digit number)
80789123491386521254…77510484723019489999
Verify on FactorDB ↗Wolfram Alpha ↗
2^2 × origin + 1
8.078 × 10⁹⁵(96-digit number)
80789123491386521254…77510484723019490001
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
1.615 × 10⁹⁶(97-digit number)
16157824698277304250…55020969446038979999
Verify on FactorDB ↗Wolfram Alpha ↗
2^3 × origin + 1
1.615 × 10⁹⁶(97-digit number)
16157824698277304250…55020969446038980001
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
3.231 × 10⁹⁶(97-digit number)
32315649396554608501…10041938892077959999
Verify on FactorDB ↗Wolfram Alpha ↗
2^4 × origin + 1
3.231 × 10⁹⁶(97-digit number)
32315649396554608501…10041938892077960001
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:57,674,410 XPM·at block #6,803,795 · updates every 60s
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