Block #289,135

TWNLength 10★★☆☆☆

Bi-Twin Chain · Discovered 12/2/2013, 1:49:42 AM · Difficulty 9.9883 · 6,509,695 confirmations

TWN
Bi-Twin Chain

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

Block Header
Block Hash
bc3dd7015d7d2cd316eda8f6b4d8fb56a3201ddecc0d4be4790efa66c3297fd9

Height

#289,135

Difficulty

9.988278

Transactions

7

Size

3.44 KB

Version

2

Bits

09fcffc6

Nonce

59,269

Timestamp

12/2/2013, 1:49:42 AM

Confirmations

6,509,695

Merkle Root

af5ff5acc1be97180dfd3216b87ced4691f3c52b307efe7a29b97d3e588f0567
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.

9.826 × 10¹⁰⁴(105-digit number)
98267044822569400769…37421809793797411839
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
9.826 × 10¹⁰⁴(105-digit number)
98267044822569400769…37421809793797411839
Verify on FactorDB ↗Wolfram Alpha ↗
origin + 1
9.826 × 10¹⁰⁴(105-digit number)
98267044822569400769…37421809793797411841
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
1.965 × 10¹⁰⁵(106-digit number)
19653408964513880153…74843619587594823679
Verify on FactorDB ↗Wolfram Alpha ↗
2^1 × origin + 1
1.965 × 10¹⁰⁵(106-digit number)
19653408964513880153…74843619587594823681
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
3.930 × 10¹⁰⁵(106-digit number)
39306817929027760307…49687239175189647359
Verify on FactorDB ↗Wolfram Alpha ↗
2^2 × origin + 1
3.930 × 10¹⁰⁵(106-digit number)
39306817929027760307…49687239175189647361
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
7.861 × 10¹⁰⁵(106-digit number)
78613635858055520615…99374478350379294719
Verify on FactorDB ↗Wolfram Alpha ↗
2^3 × origin + 1
7.861 × 10¹⁰⁵(106-digit number)
78613635858055520615…99374478350379294721
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
1.572 × 10¹⁰⁶(107-digit number)
15722727171611104123…98748956700758589439
Verify on FactorDB ↗Wolfram Alpha ↗
2^4 × origin + 1
1.572 × 10¹⁰⁶(107-digit number)
15722727171611104123…98748956700758589441
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:57,634,670 XPM·at block #6,798,829 · updates every 60s
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