Block #487,770

TWNLength 10★★☆☆☆

Bi-Twin Chain · Discovered 4/12/2014, 8:25:14 AM · Difficulty 10.6446 · 6,309,044 confirmations

TWN
Bi-Twin Chain

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

Block Header
Block Hash
d8b21e2e08ca3a47fbdc5b8abd3aea97978645b436e8ec0c6bcdfbb4433d884b

Height

#487,770

Difficulty

10.644555

Transactions

6

Size

1.27 KB

Version

2

Bits

0aa50196

Nonce

55,266

Timestamp

4/12/2014, 8:25:14 AM

Confirmations

6,309,044

Merkle Root

0264d017b1f8d5bde756af8e5891fb68dcfcb818da0a3c788842a0769f9e0bfc
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.

6.123 × 10⁹⁸(99-digit number)
61230612826180695586…57707145970713618879
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
6.123 × 10⁹⁸(99-digit number)
61230612826180695586…57707145970713618879
Verify on FactorDB ↗Wolfram Alpha ↗
origin + 1
6.123 × 10⁹⁸(99-digit number)
61230612826180695586…57707145970713618881
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
1.224 × 10⁹⁹(100-digit number)
12246122565236139117…15414291941427237759
Verify on FactorDB ↗Wolfram Alpha ↗
2^1 × origin + 1
1.224 × 10⁹⁹(100-digit number)
12246122565236139117…15414291941427237761
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
2.449 × 10⁹⁹(100-digit number)
24492245130472278234…30828583882854475519
Verify on FactorDB ↗Wolfram Alpha ↗
2^2 × origin + 1
2.449 × 10⁹⁹(100-digit number)
24492245130472278234…30828583882854475521
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
4.898 × 10⁹⁹(100-digit number)
48984490260944556468…61657167765708951039
Verify on FactorDB ↗Wolfram Alpha ↗
2^3 × origin + 1
4.898 × 10⁹⁹(100-digit number)
48984490260944556468…61657167765708951041
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
9.796 × 10⁹⁹(100-digit number)
97968980521889112937…23314335531417902079
Verify on FactorDB ↗Wolfram Alpha ↗
2^4 × origin + 1
9.796 × 10⁹⁹(100-digit number)
97968980521889112937…23314335531417902081
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:57,618,520 XPM·at block #6,796,813 · updates every 60s
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