Block #83,514

TWNLength 9★☆☆☆☆

Bi-Twin Chain · Discovered 7/26/2013, 5:13:55 AM · Difficulty 9.2676 · 6,715,970 confirmations

TWN
Bi-Twin Chain

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

Block Header
Block Hash
ca563969043ca54f41a6d133afd81ccddcf70162803674c78059590550f1a514

Height

#83,514

Difficulty

9.267638

Transactions

35

Size

14.10 KB

Version

2

Bits

094483ee

Nonce

9,354

Timestamp

7/26/2013, 5:13:55 AM

Confirmations

6,715,970

Merkle Root

ece56944ad0b253413be80773070f9bde344ec843bd946cc67ff5d4d05ddebd6
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.

6.880 × 10¹⁰¹(102-digit number)
68800148758700471011…63196269215926005279
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
6.880 × 10¹⁰¹(102-digit number)
68800148758700471011…63196269215926005279
Verify on FactorDB ↗Wolfram Alpha ↗
origin + 1
6.880 × 10¹⁰¹(102-digit number)
68800148758700471011…63196269215926005281
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
1.376 × 10¹⁰²(103-digit number)
13760029751740094202…26392538431852010559
Verify on FactorDB ↗Wolfram Alpha ↗
2^1 × origin + 1
1.376 × 10¹⁰²(103-digit number)
13760029751740094202…26392538431852010561
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
2.752 × 10¹⁰²(103-digit number)
27520059503480188404…52785076863704021119
Verify on FactorDB ↗Wolfram Alpha ↗
2^2 × origin + 1
2.752 × 10¹⁰²(103-digit number)
27520059503480188404…52785076863704021121
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
5.504 × 10¹⁰²(103-digit number)
55040119006960376809…05570153727408042239
Verify on FactorDB ↗Wolfram Alpha ↗
2^3 × origin + 1
5.504 × 10¹⁰²(103-digit number)
55040119006960376809…05570153727408042241
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
1.100 × 10¹⁰³(104-digit number)
11008023801392075361…11140307454816084479
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:57,639,914 XPM·at block #6,799,483 · updates every 60s
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