Block #309,593

TWNLength 10★★☆☆☆

Bi-Twin Chain · Discovered 12/13/2013, 4:27:40 PM · Difficulty 9.9949 · 6,481,958 confirmations

TWN
Bi-Twin Chain

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

Block Header
Block Hash
4693b1bcb3fe4e221417eb13ddca77b8484786d137b0c8d8c9ff340c1fa09019

Height

#309,593

Difficulty

9.994882

Transactions

16

Size

8.36 KB

Version

2

Bits

09feb08f

Nonce

62,829

Timestamp

12/13/2013, 4:27:40 PM

Confirmations

6,481,958

Merkle Root

77e87350142c2934e11fbd196d988e26099396bbd983df6af2575a30e0f379bd
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.

2.000 × 10⁹²(93-digit number)
20009760901788072038…65482319560017328999
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
2.000 × 10⁹²(93-digit number)
20009760901788072038…65482319560017328999
Verify on FactorDB ↗Wolfram Alpha ↗
origin + 1
2.000 × 10⁹²(93-digit number)
20009760901788072038…65482319560017329001
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
4.001 × 10⁹²(93-digit number)
40019521803576144077…30964639120034657999
Verify on FactorDB ↗Wolfram Alpha ↗
2^1 × origin + 1
4.001 × 10⁹²(93-digit number)
40019521803576144077…30964639120034658001
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
8.003 × 10⁹²(93-digit number)
80039043607152288154…61929278240069315999
Verify on FactorDB ↗Wolfram Alpha ↗
2^2 × origin + 1
8.003 × 10⁹²(93-digit number)
80039043607152288154…61929278240069316001
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
1.600 × 10⁹³(94-digit number)
16007808721430457630…23858556480138631999
Verify on FactorDB ↗Wolfram Alpha ↗
2^3 × origin + 1
1.600 × 10⁹³(94-digit number)
16007808721430457630…23858556480138632001
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
3.201 × 10⁹³(94-digit number)
32015617442860915261…47717112960277263999
Verify on FactorDB ↗Wolfram Alpha ↗
2^4 × origin + 1
3.201 × 10⁹³(94-digit number)
32015617442860915261…47717112960277264001
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:57,576,357 XPM·at block #6,791,550 · updates every 60s
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