Block #518,134

TWNLength 10★★☆☆☆

Bi-Twin Chain · Discovered 4/30/2014, 10:00:34 AM · Difficulty 10.8525 · 6,284,363 confirmations

TWN
Bi-Twin Chain

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

Block Header
Block Hash
ed26f40d3f29ee295f507471c10e1b2e033b966505e0eda976c9e5ca9a3a6de1

Height

#518,134

Difficulty

10.852509

Transactions

4

Size

1.69 KB

Version

2

Bits

0ada3e0b

Nonce

20,937

Timestamp

4/30/2014, 10:00:34 AM

Confirmations

6,284,363

Merkle Root

1d5dc2391f73a9a3472436bbd53678139b43a0042dfc4bdceb2a09e80696ddc6
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.

4.326 × 10¹¹⁰(111-digit number)
43267279960280435783…79765691960281863679
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
4.326 × 10¹¹⁰(111-digit number)
43267279960280435783…79765691960281863679
Verify on FactorDB ↗Wolfram Alpha ↗
origin + 1
4.326 × 10¹¹⁰(111-digit number)
43267279960280435783…79765691960281863681
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
8.653 × 10¹¹⁰(111-digit number)
86534559920560871566…59531383920563727359
Verify on FactorDB ↗Wolfram Alpha ↗
2^1 × origin + 1
8.653 × 10¹¹⁰(111-digit number)
86534559920560871566…59531383920563727361
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
1.730 × 10¹¹¹(112-digit number)
17306911984112174313…19062767841127454719
Verify on FactorDB ↗Wolfram Alpha ↗
2^2 × origin + 1
1.730 × 10¹¹¹(112-digit number)
17306911984112174313…19062767841127454721
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
3.461 × 10¹¹¹(112-digit number)
34613823968224348626…38125535682254909439
Verify on FactorDB ↗Wolfram Alpha ↗
2^3 × origin + 1
3.461 × 10¹¹¹(112-digit number)
34613823968224348626…38125535682254909441
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
6.922 × 10¹¹¹(112-digit number)
69227647936448697253…76251071364509818879
Verify on FactorDB ↗Wolfram Alpha ↗
2^4 × origin + 1
6.922 × 10¹¹¹(112-digit number)
69227647936448697253…76251071364509818881
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:57,663,984 XPM·at block #6,802,496 · updates every 60s
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