Block #183,095

TWNLength 9★☆☆☆☆

Bi-Twin Chain · Discovered 9/27/2013, 6:47:03 PM · Difficulty 9.8580 · 6,621,807 confirmations

TWN
Bi-Twin Chain

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

Block Header
Block Hash
cbb77a7d0c4ee9c0ccbb74bded2f7af5a8b04f70257d418cc0ca2729689994a2

Height

#183,095

Difficulty

9.857979

Transactions

4

Size

878 B

Version

2

Bits

09dba47e

Nonce

5,754

Timestamp

9/27/2013, 6:47:03 PM

Confirmations

6,621,807

Merkle Root

51585e81bf0839dc03874bd333b9a114594f1c84d58baf8d9ce53a927cb65d8e
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.

1.888 × 10⁹²(93-digit number)
18884046938412125568…50813004908349480959
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
1.888 × 10⁹²(93-digit number)
18884046938412125568…50813004908349480959
Verify on FactorDB ↗Wolfram Alpha ↗
origin + 1
1.888 × 10⁹²(93-digit number)
18884046938412125568…50813004908349480961
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
3.776 × 10⁹²(93-digit number)
37768093876824251136…01626009816698961919
Verify on FactorDB ↗Wolfram Alpha ↗
2^1 × origin + 1
3.776 × 10⁹²(93-digit number)
37768093876824251136…01626009816698961921
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
7.553 × 10⁹²(93-digit number)
75536187753648502273…03252019633397923839
Verify on FactorDB ↗Wolfram Alpha ↗
2^2 × origin + 1
7.553 × 10⁹²(93-digit number)
75536187753648502273…03252019633397923841
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
1.510 × 10⁹³(94-digit number)
15107237550729700454…06504039266795847679
Verify on FactorDB ↗Wolfram Alpha ↗
2^3 × origin + 1
1.510 × 10⁹³(94-digit number)
15107237550729700454…06504039266795847681
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
3.021 × 10⁹³(94-digit number)
30214475101459400909…13008078533591695359
Verify on FactorDB ↗Wolfram Alpha ↗

What this block proved

The miner who found this block proved the existence of 9 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
CommonChain length 9

Found in most blocks. The baseline for Primecoin's proof-of-work.

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:57,683,287 XPM·at block #6,804,901 · updates every 60s
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