Block #193

TWNLength 7★☆☆☆☆

Bi-Twin Chain · Discovered 7/7/2013, 9:24:17 PM · Difficulty 7.0043 · 6,788,711 confirmations

TWN
Bi-Twin Chain

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

Block Header
Block Hash
58b5a0fad304e84da96e3a223df63a7fd34b7a0599fb8193f0c786b036edc572

Height

#193

Difficulty

7.004298

Transactions

1

Size

208 B

Version

2

Bits

070119b2

Nonce

342

Timestamp

7/7/2013, 9:24:17 PM

Confirmations

6,788,711

Merkle Root

9f04661341467db77cdfd79be3d1d59364cab007a56424aa84cdc529583a1f88
Transactions (1)
1 in → 1 out20.3600 XPM108 B
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.

6.462 × 10¹¹⁸(119-digit number)
64623740268927598864…52083639735742881299
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
6.462 × 10¹¹⁸(119-digit number)
64623740268927598864…52083639735742881299
Verify on FactorDB ↗Wolfram Alpha ↗
origin + 1
6.462 × 10¹¹⁸(119-digit number)
64623740268927598864…52083639735742881301
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
1.292 × 10¹¹⁹(120-digit number)
12924748053785519772…04167279471485762599
Verify on FactorDB ↗Wolfram Alpha ↗
2^1 × origin + 1
1.292 × 10¹¹⁹(120-digit number)
12924748053785519772…04167279471485762601
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
2.584 × 10¹¹⁹(120-digit number)
25849496107571039545…08334558942971525199
Verify on FactorDB ↗Wolfram Alpha ↗
2^2 × origin + 1
2.584 × 10¹¹⁹(120-digit number)
25849496107571039545…08334558942971525201
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
5.169 × 10¹¹⁹(120-digit number)
51698992215142079091…16669117885943050399
Verify on FactorDB ↗Wolfram Alpha ↗

What this block proved

The miner who found this block proved the existence of 7 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 7

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:57,555,174 XPM·at block #6,788,903 · updates every 60s