Block #276,546

TWNLength 10★★☆☆☆

Bi-Twin Chain · Discovered 11/27/2013, 5:40:04 AM · Difficulty 9.9635 · 6,518,886 confirmations

TWN
Bi-Twin Chain

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

Block Header
Block Hash
6ad23138fdac5fd3e2177872dd42b866a77de5f272be553e12cb7258561bbb13

Height

#276,546

Difficulty

9.963488

Transactions

7

Size

4.96 KB

Version

2

Bits

09f6a72d

Nonce

29,283

Timestamp

11/27/2013, 5:40:04 AM

Confirmations

6,518,886

Merkle Root

7ab55edbf2cfe25dd22dae33a00ee1ca1b511518fc7fdf53c0bf42e4b104fd64
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.

5.293 × 10⁹⁵(96-digit number)
52938891257298478489…09983361681250918399
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
5.293 × 10⁹⁵(96-digit number)
52938891257298478489…09983361681250918399
Verify on FactorDB ↗Wolfram Alpha ↗
origin + 1
5.293 × 10⁹⁵(96-digit number)
52938891257298478489…09983361681250918401
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
1.058 × 10⁹⁶(97-digit number)
10587778251459695697…19966723362501836799
Verify on FactorDB ↗Wolfram Alpha ↗
2^1 × origin + 1
1.058 × 10⁹⁶(97-digit number)
10587778251459695697…19966723362501836801
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
2.117 × 10⁹⁶(97-digit number)
21175556502919391395…39933446725003673599
Verify on FactorDB ↗Wolfram Alpha ↗
2^2 × origin + 1
2.117 × 10⁹⁶(97-digit number)
21175556502919391395…39933446725003673601
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
4.235 × 10⁹⁶(97-digit number)
42351113005838782791…79866893450007347199
Verify on FactorDB ↗Wolfram Alpha ↗
2^3 × origin + 1
4.235 × 10⁹⁶(97-digit number)
42351113005838782791…79866893450007347201
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
8.470 × 10⁹⁶(97-digit number)
84702226011677565582…59733786900014694399
Verify on FactorDB ↗Wolfram Alpha ↗
2^4 × origin + 1
8.470 × 10⁹⁶(97-digit number)
84702226011677565582…59733786900014694401
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:57,607,519 XPM·at block #6,795,431 · updates every 60s
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