Block #212,590

TWNLength 9★☆☆☆☆

Bi-Twin Chain · Discovered 10/16/2013, 9:30:03 AM · Difficulty 9.9191 · 6,588,965 confirmations

TWN
Bi-Twin Chain

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

Block Header
Block Hash
c6219fc278ffcc36638aec9abdcf49bfe44b7bd894826864d17ef903a8d9d01c

Height

#212,590

Difficulty

9.919075

Transactions

3

Size

1.61 KB

Version

2

Bits

09eb4887

Nonce

25,722

Timestamp

10/16/2013, 9:30:03 AM

Confirmations

6,588,965

Merkle Root

dd6de77c33314659fb7e1928ad7755b395d412b6df8375eaec0c1641d32eeaaa
Transactions (3)
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.

1.989 × 10⁹⁰(91-digit number)
19894123501975048184…62594144607684579279
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
1.989 × 10⁹⁰(91-digit number)
19894123501975048184…62594144607684579279
Verify on FactorDB ↗Wolfram Alpha ↗
origin + 1
1.989 × 10⁹⁰(91-digit number)
19894123501975048184…62594144607684579281
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
3.978 × 10⁹⁰(91-digit number)
39788247003950096368…25188289215369158559
Verify on FactorDB ↗Wolfram Alpha ↗
2^1 × origin + 1
3.978 × 10⁹⁰(91-digit number)
39788247003950096368…25188289215369158561
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
7.957 × 10⁹⁰(91-digit number)
79576494007900192736…50376578430738317119
Verify on FactorDB ↗Wolfram Alpha ↗
2^2 × origin + 1
7.957 × 10⁹⁰(91-digit number)
79576494007900192736…50376578430738317121
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
1.591 × 10⁹¹(92-digit number)
15915298801580038547…00753156861476634239
Verify on FactorDB ↗Wolfram Alpha ↗
2^3 × origin + 1
1.591 × 10⁹¹(92-digit number)
15915298801580038547…00753156861476634241
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
3.183 × 10⁹¹(92-digit number)
31830597603160077094…01506313722953268479
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:57,656,520 XPM·at block #6,801,554 · updates every 60s
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