Block #960,526

TWNLength 11★★★☆☆

Bi-Twin Chain · Discovered 3/4/2015, 1:23:20 AM · Difficulty 10.8854 · 5,843,548 confirmations

TWN
Bi-Twin Chain

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

Block Header
Block Hash
86fed4d716450889ac2db70a2689c60228ee731da5b40d660bbad6889641277e

Height

#960,526

Difficulty

10.885379

Transactions

9

Size

1.96 KB

Version

2

Bits

0ae2a82d

Nonce

1,582,862,715

Timestamp

3/4/2015, 1:23:20 AM

Confirmations

5,843,548

Merkle Root

5233be24091e5ab5893bbea9e6fe9f7e8526e88bde1fd7d9349c2d80b6ac5d97
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.

5.495 × 10⁹⁴(95-digit number)
54951221360211315952…06199251252933817319
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
5.495 × 10⁹⁴(95-digit number)
54951221360211315952…06199251252933817319
Verify on FactorDB ↗Wolfram Alpha ↗
origin + 1
5.495 × 10⁹⁴(95-digit number)
54951221360211315952…06199251252933817321
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
1.099 × 10⁹⁵(96-digit number)
10990244272042263190…12398502505867634639
Verify on FactorDB ↗Wolfram Alpha ↗
2^1 × origin + 1
1.099 × 10⁹⁵(96-digit number)
10990244272042263190…12398502505867634641
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
2.198 × 10⁹⁵(96-digit number)
21980488544084526380…24797005011735269279
Verify on FactorDB ↗Wolfram Alpha ↗
2^2 × origin + 1
2.198 × 10⁹⁵(96-digit number)
21980488544084526380…24797005011735269281
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
4.396 × 10⁹⁵(96-digit number)
43960977088169052761…49594010023470538559
Verify on FactorDB ↗Wolfram Alpha ↗
2^3 × origin + 1
4.396 × 10⁹⁵(96-digit number)
43960977088169052761…49594010023470538561
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
8.792 × 10⁹⁵(96-digit number)
87921954176338105523…99188020046941077119
Verify on FactorDB ↗Wolfram Alpha ↗
2^4 × origin + 1
8.792 × 10⁹⁵(96-digit number)
87921954176338105523…99188020046941077121
Verify on FactorDB ↗Wolfram Alpha ↗
Difference: 2^4 × origin + 1 − 2^4 × origin − 1 = 2 (twin primes ✓)
Level 5 — Twin Prime Pair (2^5 × origin ± 1)
2^5 × origin − 1
1.758 × 10⁹⁶(97-digit number)
17584390835267621104…98376040093882154239
Verify on FactorDB ↗Wolfram Alpha ↗

What this block proved

The miner who found this block proved the existence of 11 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
RareChain length 11

Approximately 1 in 1,000 blocks. Noteworthy discoveries.

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:57,676,648 XPM·at block #6,804,073 · updates every 60s
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