Block #289,938

TWNLength 10★★☆☆☆

Bi-Twin Chain · Discovered 12/2/2013, 10:51:55 AM · Difficulty 9.9889 · 6,509,433 confirmations

TWN
Bi-Twin Chain

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

Block Header
Block Hash
ba194ce26128c2871e4edb576d0338c4a22632af8d4aa332f1f8a0d28e9c5524

Height

#289,938

Difficulty

9.988881

Transactions

8

Size

4.11 KB

Version

2

Bits

09fd274d

Nonce

67,160

Timestamp

12/2/2013, 10:51:55 AM

Confirmations

6,509,433

Merkle Root

4a06c00df0874eb5680a8b98192a1a0acc823493b8a0f2916187e99fb7560365
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.

1.354 × 10⁹²(93-digit number)
13541855260037620015…37859576460331043199
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
1.354 × 10⁹²(93-digit number)
13541855260037620015…37859576460331043199
Verify on FactorDB ↗Wolfram Alpha ↗
origin + 1
1.354 × 10⁹²(93-digit number)
13541855260037620015…37859576460331043201
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
2.708 × 10⁹²(93-digit number)
27083710520075240030…75719152920662086399
Verify on FactorDB ↗Wolfram Alpha ↗
2^1 × origin + 1
2.708 × 10⁹²(93-digit number)
27083710520075240030…75719152920662086401
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
5.416 × 10⁹²(93-digit number)
54167421040150480060…51438305841324172799
Verify on FactorDB ↗Wolfram Alpha ↗
2^2 × origin + 1
5.416 × 10⁹²(93-digit number)
54167421040150480060…51438305841324172801
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
1.083 × 10⁹³(94-digit number)
10833484208030096012…02876611682648345599
Verify on FactorDB ↗Wolfram Alpha ↗
2^3 × origin + 1
1.083 × 10⁹³(94-digit number)
10833484208030096012…02876611682648345601
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
2.166 × 10⁹³(94-digit number)
21666968416060192024…05753223365296691199
Verify on FactorDB ↗Wolfram Alpha ↗
2^4 × origin + 1
2.166 × 10⁹³(94-digit number)
21666968416060192024…05753223365296691201
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:57,639,016 XPM·at block #6,799,370 · updates every 60s
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