Block #937,402

TWNLength 10★★☆☆☆

Bi-Twin Chain · Discovered 2/15/2015, 11:00:06 AM · Difficulty 10.9008 · 5,867,824 confirmations

TWN
Bi-Twin Chain

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

Block Header
Block Hash
2d4cf41d66e508818dd7d1747da717762a30e7b9a6e2080d9fbb7219811d8590

Height

#937,402

Difficulty

10.900800

Transactions

6

Size

3.91 KB

Version

2

Bits

0ae69ad6

Nonce

252,067,471

Timestamp

2/15/2015, 11:00:06 AM

Confirmations

5,867,824

Merkle Root

57ec17336de832ada8e8fd58c3d70b85f529e29fe9b4818b07c94140a7b88b8f
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.

9.512 × 10⁹⁷(98-digit number)
95124562896032874646…94699495721737830399
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
9.512 × 10⁹⁷(98-digit number)
95124562896032874646…94699495721737830399
Verify on FactorDB ↗Wolfram Alpha ↗
origin + 1
9.512 × 10⁹⁷(98-digit number)
95124562896032874646…94699495721737830401
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
1.902 × 10⁹⁸(99-digit number)
19024912579206574929…89398991443475660799
Verify on FactorDB ↗Wolfram Alpha ↗
2^1 × origin + 1
1.902 × 10⁹⁸(99-digit number)
19024912579206574929…89398991443475660801
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
3.804 × 10⁹⁸(99-digit number)
38049825158413149858…78797982886951321599
Verify on FactorDB ↗Wolfram Alpha ↗
2^2 × origin + 1
3.804 × 10⁹⁸(99-digit number)
38049825158413149858…78797982886951321601
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
7.609 × 10⁹⁸(99-digit number)
76099650316826299716…57595965773902643199
Verify on FactorDB ↗Wolfram Alpha ↗
2^3 × origin + 1
7.609 × 10⁹⁸(99-digit number)
76099650316826299716…57595965773902643201
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
1.521 × 10⁹⁹(100-digit number)
15219930063365259943…15191931547805286399
Verify on FactorDB ↗Wolfram Alpha ↗
2^4 × origin + 1
1.521 × 10⁹⁹(100-digit number)
15219930063365259943…15191931547805286401
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:57,685,882 XPM·at block #6,805,225 · updates every 60s
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