Block #398,930

TWNLength 10★★☆☆☆

Bi-Twin Chain · Discovered 2/11/2014, 2:39:31 AM · Difficulty 10.4195 · 6,406,681 confirmations

TWN
Bi-Twin Chain

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

Block Header
Block Hash
0a1e4ef77f209431bb7f63ce6b1c88324e9d2784094bf08bf1db4668b16bb74c

Height

#398,930

Difficulty

10.419514

Transactions

1

Size

968 B

Version

2

Bits

0a6b654c

Nonce

7,092

Timestamp

2/11/2014, 2:39:31 AM

Confirmations

6,406,681

Merkle Root

a4ae68711f7d49b26ab3518273ff5294d458cee6373d85dd910794bfa856d49b
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.

2.673 × 10⁹³(94-digit number)
26733463636034977475…83920003545580799199
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
2.673 × 10⁹³(94-digit number)
26733463636034977475…83920003545580799199
Verify on FactorDB ↗Wolfram Alpha ↗
origin + 1
2.673 × 10⁹³(94-digit number)
26733463636034977475…83920003545580799201
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
5.346 × 10⁹³(94-digit number)
53466927272069954950…67840007091161598399
Verify on FactorDB ↗Wolfram Alpha ↗
2^1 × origin + 1
5.346 × 10⁹³(94-digit number)
53466927272069954950…67840007091161598401
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
1.069 × 10⁹⁴(95-digit number)
10693385454413990990…35680014182323196799
Verify on FactorDB ↗Wolfram Alpha ↗
2^2 × origin + 1
1.069 × 10⁹⁴(95-digit number)
10693385454413990990…35680014182323196801
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
2.138 × 10⁹⁴(95-digit number)
21386770908827981980…71360028364646393599
Verify on FactorDB ↗Wolfram Alpha ↗
2^3 × origin + 1
2.138 × 10⁹⁴(95-digit number)
21386770908827981980…71360028364646393601
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
4.277 × 10⁹⁴(95-digit number)
42773541817655963960…42720056729292787199
Verify on FactorDB ↗Wolfram Alpha ↗
2^4 × origin + 1
4.277 × 10⁹⁴(95-digit number)
42773541817655963960…42720056729292787201
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:57,688,962 XPM·at block #6,805,610 · updates every 60s
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