Block #328,983

TWNLength 10★★☆☆☆

Bi-Twin Chain · Discovered 12/25/2013, 3:56:51 PM · Difficulty 10.1694 · 6,465,262 confirmations

TWN
Bi-Twin Chain

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

Block Header
Block Hash
f75aefa132e6ad0eeca404081c60b24625b054e177ac180c5f940229ecc6e877

Height

#328,983

Difficulty

10.169364

Transactions

8

Size

3.13 KB

Version

2

Bits

0a2b5b78

Nonce

61,680

Timestamp

12/25/2013, 3:56:51 PM

Confirmations

6,465,262

Merkle Root

f1cf87e28c4a347d34284d1836d22d17fb1c89d69df8c6bf2435f4f88dc4f962
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.

6.648 × 10¹⁰²(103-digit number)
66487621919010041398…34068522837744567839
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
6.648 × 10¹⁰²(103-digit number)
66487621919010041398…34068522837744567839
Verify on FactorDB ↗Wolfram Alpha ↗
origin + 1
6.648 × 10¹⁰²(103-digit number)
66487621919010041398…34068522837744567841
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
1.329 × 10¹⁰³(104-digit number)
13297524383802008279…68137045675489135679
Verify on FactorDB ↗Wolfram Alpha ↗
2^1 × origin + 1
1.329 × 10¹⁰³(104-digit number)
13297524383802008279…68137045675489135681
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
2.659 × 10¹⁰³(104-digit number)
26595048767604016559…36274091350978271359
Verify on FactorDB ↗Wolfram Alpha ↗
2^2 × origin + 1
2.659 × 10¹⁰³(104-digit number)
26595048767604016559…36274091350978271361
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
5.319 × 10¹⁰³(104-digit number)
53190097535208033119…72548182701956542719
Verify on FactorDB ↗Wolfram Alpha ↗
2^3 × origin + 1
5.319 × 10¹⁰³(104-digit number)
53190097535208033119…72548182701956542721
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
1.063 × 10¹⁰⁴(105-digit number)
10638019507041606623…45096365403913085439
Verify on FactorDB ↗Wolfram Alpha ↗
2^4 × origin + 1
1.063 × 10¹⁰⁴(105-digit number)
10638019507041606623…45096365403913085441
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:57,597,992 XPM·at block #6,794,244 · updates every 60s
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