Block #276,802

TWNLength 9★☆☆☆☆

Bi-Twin Chain · Discovered 11/27/2013, 8:08:25 AM · Difficulty 9.9643 · 6,517,385 confirmations

TWN
Bi-Twin Chain

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

Block Header
Block Hash
e91de1b57f79fe2ff5fea2031efa10e8e9c7281a5985c609fd416faced200f49

Height

#276,802

Difficulty

9.964268

Transactions

8

Size

2.62 KB

Version

2

Bits

09f6da4b

Nonce

102,964

Timestamp

11/27/2013, 8:08:25 AM

Confirmations

6,517,385

Merkle Root

cde9c41fdf7844fe5fecf6b5a159e67063f250e0f07d26f02c2452327e2411f2
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.

6.206 × 10⁹³(94-digit number)
62060840830071810881…24629799093719768479
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
6.206 × 10⁹³(94-digit number)
62060840830071810881…24629799093719768479
Verify on FactorDB ↗Wolfram Alpha ↗
origin + 1
6.206 × 10⁹³(94-digit number)
62060840830071810881…24629799093719768481
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
1.241 × 10⁹⁴(95-digit number)
12412168166014362176…49259598187439536959
Verify on FactorDB ↗Wolfram Alpha ↗
2^1 × origin + 1
1.241 × 10⁹⁴(95-digit number)
12412168166014362176…49259598187439536961
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
2.482 × 10⁹⁴(95-digit number)
24824336332028724352…98519196374879073919
Verify on FactorDB ↗Wolfram Alpha ↗
2^2 × origin + 1
2.482 × 10⁹⁴(95-digit number)
24824336332028724352…98519196374879073921
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
4.964 × 10⁹⁴(95-digit number)
49648672664057448705…97038392749758147839
Verify on FactorDB ↗Wolfram Alpha ↗
2^3 × origin + 1
4.964 × 10⁹⁴(95-digit number)
49648672664057448705…97038392749758147841
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
9.929 × 10⁹⁴(95-digit number)
99297345328114897410…94076785499516295679
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:57,597,518 XPM·at block #6,794,186 · updates every 60s
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