Block #620,709

TWNLength 10★★☆☆☆

Bi-Twin Chain · Discovered 7/7/2014, 1:20:27 AM · Difficulty 10.9506 · 6,171,869 confirmations

TWN
Bi-Twin Chain

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

Block Header
Block Hash
56b02b6223bf6b5cbad7f335581b6db456e1372ef0cd74f6f1c011a23932df7c

Height

#620,709

Difficulty

10.950551

Transactions

9

Size

2.11 KB

Version

2

Bits

0af3574b

Nonce

386,605,178

Timestamp

7/7/2014, 1:20:27 AM

Confirmations

6,171,869

Merkle Root

00a692c3618a82b81316d446a781a50f405f012aad1a87d443640de85600f978
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.

2.287 × 10⁹⁵(96-digit number)
22871967546059822963…34777436496057589799
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
2.287 × 10⁹⁵(96-digit number)
22871967546059822963…34777436496057589799
Verify on FactorDB ↗Wolfram Alpha ↗
origin + 1
2.287 × 10⁹⁵(96-digit number)
22871967546059822963…34777436496057589801
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
4.574 × 10⁹⁵(96-digit number)
45743935092119645927…69554872992115179599
Verify on FactorDB ↗Wolfram Alpha ↗
2^1 × origin + 1
4.574 × 10⁹⁵(96-digit number)
45743935092119645927…69554872992115179601
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
9.148 × 10⁹⁵(96-digit number)
91487870184239291854…39109745984230359199
Verify on FactorDB ↗Wolfram Alpha ↗
2^2 × origin + 1
9.148 × 10⁹⁵(96-digit number)
91487870184239291854…39109745984230359201
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
1.829 × 10⁹⁶(97-digit number)
18297574036847858370…78219491968460718399
Verify on FactorDB ↗Wolfram Alpha ↗
2^3 × origin + 1
1.829 × 10⁹⁶(97-digit number)
18297574036847858370…78219491968460718401
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
3.659 × 10⁹⁶(97-digit number)
36595148073695716741…56438983936921436799
Verify on FactorDB ↗Wolfram Alpha ↗
2^4 × origin + 1
3.659 × 10⁹⁶(97-digit number)
36595148073695716741…56438983936921436801
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:57,584,592 XPM·at block #6,792,577 · updates every 60s
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