Block #162,712

TWNLength 10★★☆☆☆

Bi-Twin Chain · Discovered 9/13/2013, 12:17:12 PM · Difficulty 9.8613 · 6,642,343 confirmations

TWN
Bi-Twin Chain

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

Block Header
Block Hash
39cff4f88d6c9ca943500f8b9c9b973d1015a8f59981325d4f418ba7ac19334c

Height

#162,712

Difficulty

9.861273

Transactions

3

Size

798 B

Version

2

Bits

09dc7c64

Nonce

30,871

Timestamp

9/13/2013, 12:17:12 PM

Confirmations

6,642,343

Merkle Root

ab8d89dbfc7fc827cad46d975a90115fcba7fe335def66a8efc4676a92e60ea7
Transactions (3)
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.

2.410 × 10⁹¹(92-digit number)
24106131456638415378…13408079722246553599
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
2.410 × 10⁹¹(92-digit number)
24106131456638415378…13408079722246553599
Verify on FactorDB ↗Wolfram Alpha ↗
origin + 1
2.410 × 10⁹¹(92-digit number)
24106131456638415378…13408079722246553601
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
4.821 × 10⁹¹(92-digit number)
48212262913276830756…26816159444493107199
Verify on FactorDB ↗Wolfram Alpha ↗
2^1 × origin + 1
4.821 × 10⁹¹(92-digit number)
48212262913276830756…26816159444493107201
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
9.642 × 10⁹¹(92-digit number)
96424525826553661513…53632318888986214399
Verify on FactorDB ↗Wolfram Alpha ↗
2^2 × origin + 1
9.642 × 10⁹¹(92-digit number)
96424525826553661513…53632318888986214401
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
1.928 × 10⁹²(93-digit number)
19284905165310732302…07264637777972428799
Verify on FactorDB ↗Wolfram Alpha ↗
2^3 × origin + 1
1.928 × 10⁹²(93-digit number)
19284905165310732302…07264637777972428801
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
3.856 × 10⁹²(93-digit number)
38569810330621464605…14529275555944857599
Verify on FactorDB ↗Wolfram Alpha ↗
2^4 × origin + 1
3.856 × 10⁹²(93-digit number)
38569810330621464605…14529275555944857601
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:57,684,505 XPM·at block #6,805,054 · updates every 60s
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