Block #316,883

TWNLength 10★★☆☆☆

Bi-Twin Chain · Discovered 12/17/2013, 8:15:42 AM · Difficulty 10.1461 · 6,477,383 confirmations

TWN
Bi-Twin Chain

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

Block Header
Block Hash
165cea7f7ce4e73f7c47a19f85f1cf224b31ee479bfe5f00443d4a55940fe252

Height

#316,883

Difficulty

10.146108

Transactions

20

Size

7.56 KB

Version

2

Bits

0a25675c

Nonce

34,268

Timestamp

12/17/2013, 8:15:42 AM

Confirmations

6,477,383

Merkle Root

13c51c3ecae2a10611409be44de7fa5bcdc7f91da5d8339b83d92f8951144593
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.

1.934 × 10¹⁰¹(102-digit number)
19342349737422413498…74142488059139022719
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
1.934 × 10¹⁰¹(102-digit number)
19342349737422413498…74142488059139022719
Verify on FactorDB ↗Wolfram Alpha ↗
origin + 1
1.934 × 10¹⁰¹(102-digit number)
19342349737422413498…74142488059139022721
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
3.868 × 10¹⁰¹(102-digit number)
38684699474844826996…48284976118278045439
Verify on FactorDB ↗Wolfram Alpha ↗
2^1 × origin + 1
3.868 × 10¹⁰¹(102-digit number)
38684699474844826996…48284976118278045441
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
7.736 × 10¹⁰¹(102-digit number)
77369398949689653992…96569952236556090879
Verify on FactorDB ↗Wolfram Alpha ↗
2^2 × origin + 1
7.736 × 10¹⁰¹(102-digit number)
77369398949689653992…96569952236556090881
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
1.547 × 10¹⁰²(103-digit number)
15473879789937930798…93139904473112181759
Verify on FactorDB ↗Wolfram Alpha ↗
2^3 × origin + 1
1.547 × 10¹⁰²(103-digit number)
15473879789937930798…93139904473112181761
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
3.094 × 10¹⁰²(103-digit number)
30947759579875861596…86279808946224363519
Verify on FactorDB ↗Wolfram Alpha ↗
2^4 × origin + 1
3.094 × 10¹⁰²(103-digit number)
30947759579875861596…86279808946224363521
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:57,598,156 XPM·at block #6,794,265 · updates every 60s
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