Block #337,515

TWNLength 10★★☆☆☆

Bi-Twin Chain · Discovered 12/31/2013, 5:56:32 PM · Difficulty 10.1347 · 6,455,263 confirmations

TWN
Bi-Twin Chain

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

Block Header
Block Hash
25928e246bea615679a3b8f79f45b30baaa59387694a44f283ba5e2d70b1d91f

Height

#337,515

Difficulty

10.134686

Transactions

19

Size

5.21 KB

Version

2

Bits

0a227ad0

Nonce

209,167

Timestamp

12/31/2013, 5:56:32 PM

Confirmations

6,455,263

Merkle Root

55e96443dcb13c3aad06dfd38ba8624b2d213a984d00c6abda714508695e9c9b
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.

2.764 × 10⁹¹(92-digit number)
27647631633282270762…08130872424800089329
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
2.764 × 10⁹¹(92-digit number)
27647631633282270762…08130872424800089329
Verify on FactorDB ↗Wolfram Alpha ↗
origin + 1
2.764 × 10⁹¹(92-digit number)
27647631633282270762…08130872424800089331
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
5.529 × 10⁹¹(92-digit number)
55295263266564541525…16261744849600178659
Verify on FactorDB ↗Wolfram Alpha ↗
2^1 × origin + 1
5.529 × 10⁹¹(92-digit number)
55295263266564541525…16261744849600178661
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
1.105 × 10⁹²(93-digit number)
11059052653312908305…32523489699200357319
Verify on FactorDB ↗Wolfram Alpha ↗
2^2 × origin + 1
1.105 × 10⁹²(93-digit number)
11059052653312908305…32523489699200357321
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
2.211 × 10⁹²(93-digit number)
22118105306625816610…65046979398400714639
Verify on FactorDB ↗Wolfram Alpha ↗
2^3 × origin + 1
2.211 × 10⁹²(93-digit number)
22118105306625816610…65046979398400714641
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
4.423 × 10⁹²(93-digit number)
44236210613251633220…30093958796801429279
Verify on FactorDB ↗Wolfram Alpha ↗
2^4 × origin + 1
4.423 × 10⁹²(93-digit number)
44236210613251633220…30093958796801429281
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:57,586,205 XPM·at block #6,792,777 · updates every 60s
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