Block #357,430

TWNLength 10★★☆☆☆

Bi-Twin Chain · Discovered 1/13/2014, 10:07:06 AM · Difficulty 10.3834 · 6,448,745 confirmations

TWN
Bi-Twin Chain

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

Block Header
Block Hash
ac5fbc34ab3bbce8698fe6ea8e5053162322630044b5619dfd4aaf9aaedf8159

Height

#357,430

Difficulty

10.383351

Transactions

1

Size

1.08 KB

Version

2

Bits

0a622350

Nonce

9,385

Timestamp

1/13/2014, 10:07:06 AM

Confirmations

6,448,745

Merkle Root

2d292e0307ac1024711f1f3faa0671cf04ead01cbbce08016bccb9fdfc922e7c
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.

4.017 × 10¹⁰⁷(108-digit number)
40170464266074481476…03640977596515673599
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
4.017 × 10¹⁰⁷(108-digit number)
40170464266074481476…03640977596515673599
Verify on FactorDB ↗Wolfram Alpha ↗
origin + 1
4.017 × 10¹⁰⁷(108-digit number)
40170464266074481476…03640977596515673601
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
8.034 × 10¹⁰⁷(108-digit number)
80340928532148962952…07281955193031347199
Verify on FactorDB ↗Wolfram Alpha ↗
2^1 × origin + 1
8.034 × 10¹⁰⁷(108-digit number)
80340928532148962952…07281955193031347201
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
1.606 × 10¹⁰⁸(109-digit number)
16068185706429792590…14563910386062694399
Verify on FactorDB ↗Wolfram Alpha ↗
2^2 × origin + 1
1.606 × 10¹⁰⁸(109-digit number)
16068185706429792590…14563910386062694401
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
3.213 × 10¹⁰⁸(109-digit number)
32136371412859585180…29127820772125388799
Verify on FactorDB ↗Wolfram Alpha ↗
2^3 × origin + 1
3.213 × 10¹⁰⁸(109-digit number)
32136371412859585180…29127820772125388801
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
6.427 × 10¹⁰⁸(109-digit number)
64272742825719170361…58255641544250777599
Verify on FactorDB ↗Wolfram Alpha ↗
2^4 × origin + 1
6.427 × 10¹⁰⁸(109-digit number)
64272742825719170361…58255641544250777601
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:57,693,483 XPM·at block #6,806,174 · updates every 60s
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