Block #162,946

TWNLength 10★★☆☆☆

Bi-Twin Chain · Discovered 9/13/2013, 3:58:37 PM · Difficulty 9.8616 · 6,626,965 confirmations

TWN
Bi-Twin Chain

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

Block Header
Block Hash
90ef36c80d3dc3fddc1f30026ff379910d5e28909aeee5aa9d9b86002f0272ef

Height

#162,946

Difficulty

9.861643

Transactions

9

Size

2.11 KB

Version

2

Bits

09dc94a1

Nonce

31,013

Timestamp

9/13/2013, 3:58:37 PM

Confirmations

6,626,965

Merkle Root

a780e9a9583f642d0eacde8ef000d1db52e45aa3dbdca62db2397f8a5e56217c
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.

8.348 × 10⁹⁶(97-digit number)
83488408725747627752…14815470072101807999
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
8.348 × 10⁹⁶(97-digit number)
83488408725747627752…14815470072101807999
Verify on FactorDB ↗Wolfram Alpha ↗
origin + 1
8.348 × 10⁹⁶(97-digit number)
83488408725747627752…14815470072101808001
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
1.669 × 10⁹⁷(98-digit number)
16697681745149525550…29630940144203615999
Verify on FactorDB ↗Wolfram Alpha ↗
2^1 × origin + 1
1.669 × 10⁹⁷(98-digit number)
16697681745149525550…29630940144203616001
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
3.339 × 10⁹⁷(98-digit number)
33395363490299051100…59261880288407231999
Verify on FactorDB ↗Wolfram Alpha ↗
2^2 × origin + 1
3.339 × 10⁹⁷(98-digit number)
33395363490299051100…59261880288407232001
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
6.679 × 10⁹⁷(98-digit number)
66790726980598102201…18523760576814463999
Verify on FactorDB ↗Wolfram Alpha ↗
2^3 × origin + 1
6.679 × 10⁹⁷(98-digit number)
66790726980598102201…18523760576814464001
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
1.335 × 10⁹⁸(99-digit number)
13358145396119620440…37047521153628927999
Verify on FactorDB ↗Wolfram Alpha ↗
2^4 × origin + 1
1.335 × 10⁹⁸(99-digit number)
13358145396119620440…37047521153628928001
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:57,563,266 XPM·at block #6,789,910 · updates every 60s