Block #270,409

TWNLength 9★☆☆☆☆

Bi-Twin Chain · Discovered 11/23/2013, 10:18:47 PM · Difficulty 9.9518 · 6,519,373 confirmations

TWN
Bi-Twin Chain

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

Block Header
Block Hash
a9be96278f91dbaa164dc6c0f90328675ef7621f66f03eb86d1479b8a5eb675f

Height

#270,409

Difficulty

9.951819

Transactions

10

Size

19.59 KB

Version

2

Bits

09f3aa6c

Nonce

4,041

Timestamp

11/23/2013, 10:18:47 PM

Confirmations

6,519,373

Merkle Root

54a9b89ba705f79a6d6f1e60ee7de65e5fe727bcf0b8ea7dd9cae3451d5b846c
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.

6.320 × 10⁹¹(92-digit number)
63206992052277553642…99763506718295929919
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
6.320 × 10⁹¹(92-digit number)
63206992052277553642…99763506718295929919
Verify on FactorDB ↗Wolfram Alpha ↗
origin + 1
6.320 × 10⁹¹(92-digit number)
63206992052277553642…99763506718295929921
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
1.264 × 10⁹²(93-digit number)
12641398410455510728…99527013436591859839
Verify on FactorDB ↗Wolfram Alpha ↗
2^1 × origin + 1
1.264 × 10⁹²(93-digit number)
12641398410455510728…99527013436591859841
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
2.528 × 10⁹²(93-digit number)
25282796820911021457…99054026873183719679
Verify on FactorDB ↗Wolfram Alpha ↗
2^2 × origin + 1
2.528 × 10⁹²(93-digit number)
25282796820911021457…99054026873183719681
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
5.056 × 10⁹²(93-digit number)
50565593641822042914…98108053746367439359
Verify on FactorDB ↗Wolfram Alpha ↗
2^3 × origin + 1
5.056 × 10⁹²(93-digit number)
50565593641822042914…98108053746367439361
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
1.011 × 10⁹³(94-digit number)
10113118728364408582…96216107492734878719
Verify on FactorDB ↗Wolfram Alpha ↗

What this block proved

The miner who found this block proved the existence of 9 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
CommonChain length 9

Found in most blocks. The baseline for Primecoin's proof-of-work.

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:57,562,226 XPM·at block #6,789,781 · updates every 60s