Block #486,781

TWNLength 10★★☆☆☆

Bi-Twin Chain · Discovered 4/11/2014, 6:58:04 PM · Difficulty 10.6317 · 6,309,665 confirmations

TWN
Bi-Twin Chain

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

Block Header
Block Hash
b4849f1fffefa1835cbfa7297e777ba7c1a8e7b301b6074a7cd24c7d48d3932c

Height

#486,781

Difficulty

10.631701

Transactions

6

Size

2.35 KB

Version

2

Bits

0aa1b729

Nonce

112,782

Timestamp

4/11/2014, 6:58:04 PM

Confirmations

6,309,665

Merkle Root

760a5c108f07c945fae3e039a710daff788f1999d0be73cbedeb2f44766cdf99
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.

9.102 × 10⁹⁹(100-digit number)
91020431019234418321…15033183883573201999
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
9.102 × 10⁹⁹(100-digit number)
91020431019234418321…15033183883573201999
Verify on FactorDB ↗Wolfram Alpha ↗
origin + 1
9.102 × 10⁹⁹(100-digit number)
91020431019234418321…15033183883573202001
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
1.820 × 10¹⁰⁰(101-digit number)
18204086203846883664…30066367767146403999
Verify on FactorDB ↗Wolfram Alpha ↗
2^1 × origin + 1
1.820 × 10¹⁰⁰(101-digit number)
18204086203846883664…30066367767146404001
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
3.640 × 10¹⁰⁰(101-digit number)
36408172407693767328…60132735534292807999
Verify on FactorDB ↗Wolfram Alpha ↗
2^2 × origin + 1
3.640 × 10¹⁰⁰(101-digit number)
36408172407693767328…60132735534292808001
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
7.281 × 10¹⁰⁰(101-digit number)
72816344815387534657…20265471068585615999
Verify on FactorDB ↗Wolfram Alpha ↗
2^3 × origin + 1
7.281 × 10¹⁰⁰(101-digit number)
72816344815387534657…20265471068585616001
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
1.456 × 10¹⁰¹(102-digit number)
14563268963077506931…40530942137171231999
Verify on FactorDB ↗Wolfram Alpha ↗
2^4 × origin + 1
1.456 × 10¹⁰¹(102-digit number)
14563268963077506931…40530942137171232001
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:57,615,561 XPM·at block #6,796,445 · updates every 60s
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