Block #390,989

TWNLength 11★★★☆☆

Bi-Twin Chain · Discovered 2/5/2014, 12:56:58 PM · Difficulty 10.4261 · 6,412,721 confirmations

TWN
Bi-Twin Chain

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

Block Header
Block Hash
5122b04dc70452b7bd4906b119dddf73fa560c9d4da746a20406c67638c667e2

Height

#390,989

Difficulty

10.426146

Transactions

4

Size

2.34 KB

Version

2

Bits

0a6d17e3

Nonce

95,460

Timestamp

2/5/2014, 12:56:58 PM

Confirmations

6,412,721

Merkle Root

c2a6b20d87287c16c225c170eac7f4dd2049ca4aaffcff938275caa2dcb81198
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.

6.553 × 10⁹⁶(97-digit number)
65537626213630451508…10122864935711457449
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
6.553 × 10⁹⁶(97-digit number)
65537626213630451508…10122864935711457449
Verify on FactorDB ↗Wolfram Alpha ↗
origin + 1
6.553 × 10⁹⁶(97-digit number)
65537626213630451508…10122864935711457451
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
1.310 × 10⁹⁷(98-digit number)
13107525242726090301…20245729871422914899
Verify on FactorDB ↗Wolfram Alpha ↗
2^1 × origin + 1
1.310 × 10⁹⁷(98-digit number)
13107525242726090301…20245729871422914901
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
2.621 × 10⁹⁷(98-digit number)
26215050485452180603…40491459742845829799
Verify on FactorDB ↗Wolfram Alpha ↗
2^2 × origin + 1
2.621 × 10⁹⁷(98-digit number)
26215050485452180603…40491459742845829801
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
5.243 × 10⁹⁷(98-digit number)
52430100970904361206…80982919485691659599
Verify on FactorDB ↗Wolfram Alpha ↗
2^3 × origin + 1
5.243 × 10⁹⁷(98-digit number)
52430100970904361206…80982919485691659601
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
1.048 × 10⁹⁸(99-digit number)
10486020194180872241…61965838971383319199
Verify on FactorDB ↗Wolfram Alpha ↗
2^4 × origin + 1
1.048 × 10⁹⁸(99-digit number)
10486020194180872241…61965838971383319201
Verify on FactorDB ↗Wolfram Alpha ↗
Difference: 2^4 × origin + 1 − 2^4 × origin − 1 = 2 (twin primes ✓)
Level 5 — Twin Prime Pair (2^5 × origin ± 1)
2^5 × origin − 1
2.097 × 10⁹⁸(99-digit number)
20972040388361744482…23931677942766638399
Verify on FactorDB ↗Wolfram Alpha ↗

What this block proved

The miner who found this block proved the existence of 11 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
RareChain length 11

Approximately 1 in 1,000 blocks. Noteworthy discoveries.

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:57,673,720 XPM·at block #6,803,709 · updates every 60s
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