Block #253,082

TWNLength 10★★☆☆☆

Bi-Twin Chain · Discovered 11/9/2013, 10:43:32 PM · Difficulty 9.9718 · 6,536,703 confirmations

TWN
Bi-Twin Chain

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

Block Header
Block Hash
6938ddbe85e69b77170fe923afb1f515c68fa0e689ae4c1e6d2ca3c953d22a6d

Height

#253,082

Difficulty

9.971842

Transactions

6

Size

2.46 KB

Version

2

Bits

09f8ca9b

Nonce

43,306

Timestamp

11/9/2013, 10:43:32 PM

Confirmations

6,536,703

Merkle Root

fc07862a2aa26b026a84ed435f1819d5b9361a181763662190e2c4d678521b61
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.

9.335 × 10⁹³(94-digit number)
93350335536303046022…79959128043404981759
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
9.335 × 10⁹³(94-digit number)
93350335536303046022…79959128043404981759
Verify on FactorDB ↗Wolfram Alpha ↗
origin + 1
9.335 × 10⁹³(94-digit number)
93350335536303046022…79959128043404981761
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
1.867 × 10⁹⁴(95-digit number)
18670067107260609204…59918256086809963519
Verify on FactorDB ↗Wolfram Alpha ↗
2^1 × origin + 1
1.867 × 10⁹⁴(95-digit number)
18670067107260609204…59918256086809963521
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
3.734 × 10⁹⁴(95-digit number)
37340134214521218409…19836512173619927039
Verify on FactorDB ↗Wolfram Alpha ↗
2^2 × origin + 1
3.734 × 10⁹⁴(95-digit number)
37340134214521218409…19836512173619927041
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
7.468 × 10⁹⁴(95-digit number)
74680268429042436818…39673024347239854079
Verify on FactorDB ↗Wolfram Alpha ↗
2^3 × origin + 1
7.468 × 10⁹⁴(95-digit number)
74680268429042436818…39673024347239854081
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
1.493 × 10⁹⁵(96-digit number)
14936053685808487363…79346048694479708159
Verify on FactorDB ↗Wolfram Alpha ↗
2^4 × origin + 1
1.493 × 10⁹⁵(96-digit number)
14936053685808487363…79346048694479708161
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:57,562,250 XPM·at block #6,789,784 · updates every 60s