Block #207,060

TWNLength 10★★☆☆☆

Bi-Twin Chain · Discovered 10/13/2013, 5:24:56 AM · Difficulty 9.9017 · 6,596,243 confirmations

TWN
Bi-Twin Chain

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

Block Header
Block Hash
8efa61ce6774edd68241f8141141d93c42d3f2f89c9a719c500f8ab86a484647

Height

#207,060

Difficulty

9.901704

Transactions

2

Size

928 B

Version

2

Bits

09e6d60e

Nonce

3,222

Timestamp

10/13/2013, 5:24:56 AM

Confirmations

6,596,243

Merkle Root

a170223ad1d4f1c981023d6450645e5ce2ac1d18df0912ea6f44313da6f5bf25
Transactions (2)
1 in → 1 out10.1900 XPM109 B
6 in → 1 out61.2300 XPM731 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.

1.862 × 10⁸⁹(90-digit number)
18627247057858146783…29236766664665163549
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
1.862 × 10⁸⁹(90-digit number)
18627247057858146783…29236766664665163549
Verify on FactorDB ↗Wolfram Alpha ↗
origin + 1
1.862 × 10⁸⁹(90-digit number)
18627247057858146783…29236766664665163551
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
3.725 × 10⁸⁹(90-digit number)
37254494115716293567…58473533329330327099
Verify on FactorDB ↗Wolfram Alpha ↗
2^1 × origin + 1
3.725 × 10⁸⁹(90-digit number)
37254494115716293567…58473533329330327101
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
7.450 × 10⁸⁹(90-digit number)
74508988231432587134…16947066658660654199
Verify on FactorDB ↗Wolfram Alpha ↗
2^2 × origin + 1
7.450 × 10⁸⁹(90-digit number)
74508988231432587134…16947066658660654201
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
1.490 × 10⁹⁰(91-digit number)
14901797646286517426…33894133317321308399
Verify on FactorDB ↗Wolfram Alpha ↗
2^3 × origin + 1
1.490 × 10⁹⁰(91-digit number)
14901797646286517426…33894133317321308401
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
2.980 × 10⁹⁰(91-digit number)
29803595292573034853…67788266634642616799
Verify on FactorDB ↗Wolfram Alpha ↗
2^4 × origin + 1
2.980 × 10⁹⁰(91-digit number)
29803595292573034853…67788266634642616801
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:57,670,451 XPM·at block #6,803,302 · updates every 60s
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