Block #198,214

TWNLength 9★☆☆☆☆

Bi-Twin Chain · Discovered 10/7/2013, 2:59:57 PM · Difficulty 9.8846 · 6,591,617 confirmations

TWN
Bi-Twin Chain

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

Block Header
Block Hash
42b1a9a1be1f2660a3eb1bd7f8ebaed1b96fc7a7234a029ac54268e1cb97958a

Height

#198,214

Difficulty

9.884607

Transactions

15

Size

90.76 KB

Version

2

Bits

09e275a0

Nonce

24,874

Timestamp

10/7/2013, 2:59:57 PM

Confirmations

6,591,617

Merkle Root

6110d6101690192ef7275021738185b7a26f118bcc707b6a101c73ea2d0d2a4f
Transactions (15)
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.

1.496 × 10⁹³(94-digit number)
14962662987032682449…26326066158127523199
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
1.496 × 10⁹³(94-digit number)
14962662987032682449…26326066158127523199
Verify on FactorDB ↗Wolfram Alpha ↗
origin + 1
1.496 × 10⁹³(94-digit number)
14962662987032682449…26326066158127523201
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
2.992 × 10⁹³(94-digit number)
29925325974065364899…52652132316255046399
Verify on FactorDB ↗Wolfram Alpha ↗
2^1 × origin + 1
2.992 × 10⁹³(94-digit number)
29925325974065364899…52652132316255046401
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
5.985 × 10⁹³(94-digit number)
59850651948130729799…05304264632510092799
Verify on FactorDB ↗Wolfram Alpha ↗
2^2 × origin + 1
5.985 × 10⁹³(94-digit number)
59850651948130729799…05304264632510092801
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
1.197 × 10⁹⁴(95-digit number)
11970130389626145959…10608529265020185599
Verify on FactorDB ↗Wolfram Alpha ↗
2^3 × origin + 1
1.197 × 10⁹⁴(95-digit number)
11970130389626145959…10608529265020185601
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
2.394 × 10⁹⁴(95-digit number)
23940260779252291919…21217058530040371199
Verify on FactorDB ↗Wolfram Alpha ↗

What this block proved

The miner who found this block proved the existence of 9 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
CommonChain length 9

Found in most blocks. The baseline for Primecoin's proof-of-work.

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:57,562,619 XPM·at block #6,789,830 · updates every 60s