Block #285,084

TWNLength 10★★☆☆☆

Bi-Twin Chain · Discovered 11/30/2013, 9:02:26 AM · Difficulty 9.9837 · 6,511,735 confirmations

TWN
Bi-Twin Chain

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

Block Header
Block Hash
7ac514fbe6fbe1bafb2224574826ef8e481cd8b760e69f613aa1bfdf1101e46f

Height

#285,084

Difficulty

9.983729

Transactions

8

Size

1.77 KB

Version

2

Bits

09fbd5a9

Nonce

31,661

Timestamp

11/30/2013, 9:02:26 AM

Confirmations

6,511,735

Merkle Root

64c94c6063c5bfded7a2d6b905820ca8d400e6a56ac125e7dcd9c17efa92a490
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.

2.784 × 10¹⁰⁴(105-digit number)
27842008672792565880…38324105997443010839
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
2.784 × 10¹⁰⁴(105-digit number)
27842008672792565880…38324105997443010839
Verify on FactorDB ↗Wolfram Alpha ↗
origin + 1
2.784 × 10¹⁰⁴(105-digit number)
27842008672792565880…38324105997443010841
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
5.568 × 10¹⁰⁴(105-digit number)
55684017345585131761…76648211994886021679
Verify on FactorDB ↗Wolfram Alpha ↗
2^1 × origin + 1
5.568 × 10¹⁰⁴(105-digit number)
55684017345585131761…76648211994886021681
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
1.113 × 10¹⁰⁵(106-digit number)
11136803469117026352…53296423989772043359
Verify on FactorDB ↗Wolfram Alpha ↗
2^2 × origin + 1
1.113 × 10¹⁰⁵(106-digit number)
11136803469117026352…53296423989772043361
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
2.227 × 10¹⁰⁵(106-digit number)
22273606938234052704…06592847979544086719
Verify on FactorDB ↗Wolfram Alpha ↗
2^3 × origin + 1
2.227 × 10¹⁰⁵(106-digit number)
22273606938234052704…06592847979544086721
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
4.454 × 10¹⁰⁵(106-digit number)
44547213876468105409…13185695959088173439
Verify on FactorDB ↗Wolfram Alpha ↗
2^4 × origin + 1
4.454 × 10¹⁰⁵(106-digit number)
44547213876468105409…13185695959088173441
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:57,618,561 XPM·at block #6,796,818 · updates every 60s
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