Block #922,409

TWNLength 10★★☆☆☆

Bi-Twin Chain · Discovered 2/4/2015, 11:07:43 AM · Difficulty 10.9155 · 5,876,560 confirmations

TWN
Bi-Twin Chain

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

Block Header
Block Hash
23abb6cf3bfcda62cacdc31822a7f9df119fc1a61e12bd8e5592bbc290dde894

Height

#922,409

Difficulty

10.915458

Transactions

5

Size

115.95 KB

Version

2

Bits

0aea5b74

Nonce

683,579,264

Timestamp

2/4/2015, 11:07:43 AM

Confirmations

5,876,560

Merkle Root

2cdefbae8319e29d07f0b42abd121b0210bc53d110fd4e1f2b053dc43dae5c60
Transactions (5)
1 in → 1 out9.5800 XPM116 B
200 in → 1 out964.6544 XPM28.94 KB
200 in → 1 out1017.1450 XPM28.93 KB
200 in → 1 out955.8844 XPM28.94 KB
200 in → 1 out1117.5118 XPM28.95 KB
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.

2.809 × 10⁹⁵(96-digit number)
28090771587741157683…36058585598681309119
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
2.809 × 10⁹⁵(96-digit number)
28090771587741157683…36058585598681309119
Verify on FactorDB ↗Wolfram Alpha ↗
origin + 1
2.809 × 10⁹⁵(96-digit number)
28090771587741157683…36058585598681309121
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
5.618 × 10⁹⁵(96-digit number)
56181543175482315367…72117171197362618239
Verify on FactorDB ↗Wolfram Alpha ↗
2^1 × origin + 1
5.618 × 10⁹⁵(96-digit number)
56181543175482315367…72117171197362618241
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
1.123 × 10⁹⁶(97-digit number)
11236308635096463073…44234342394725236479
Verify on FactorDB ↗Wolfram Alpha ↗
2^2 × origin + 1
1.123 × 10⁹⁶(97-digit number)
11236308635096463073…44234342394725236481
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
2.247 × 10⁹⁶(97-digit number)
22472617270192926147…88468684789450472959
Verify on FactorDB ↗Wolfram Alpha ↗
2^3 × origin + 1
2.247 × 10⁹⁶(97-digit number)
22472617270192926147…88468684789450472961
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
4.494 × 10⁹⁶(97-digit number)
44945234540385852294…76937369578900945919
Verify on FactorDB ↗Wolfram Alpha ↗
2^4 × origin + 1
4.494 × 10⁹⁶(97-digit number)
44945234540385852294…76937369578900945921
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:57,635,788 XPM·at block #6,798,968 · updates every 60s
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