Block #119,851

TWNLength 9★☆☆☆☆

Bi-Twin Chain · Discovered 8/16/2013, 6:04:23 PM · Difficulty 9.7515 · 6,684,227 confirmations

TWN
Bi-Twin Chain

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

Block Header
Block Hash
6d8a696902e6f89334e78703368ffcb0f188021357c1fd15c6cf3facb69ca57d

Height

#119,851

Difficulty

9.751512

Transactions

7

Size

15.96 KB

Version

2

Bits

09c0631d

Nonce

61,793

Timestamp

8/16/2013, 6:04:23 PM

Confirmations

6,684,227

Merkle Root

3d330b7139f9f1740a2f5c8900e6afe675c143b48d9aaf5c08f4832d8f81f061
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.

8.496 × 10⁹⁹(100-digit number)
84960019853926303252…43029710085431303979
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
8.496 × 10⁹⁹(100-digit number)
84960019853926303252…43029710085431303979
Verify on FactorDB ↗Wolfram Alpha ↗
origin + 1
8.496 × 10⁹⁹(100-digit number)
84960019853926303252…43029710085431303981
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
1.699 × 10¹⁰⁰(101-digit number)
16992003970785260650…86059420170862607959
Verify on FactorDB ↗Wolfram Alpha ↗
2^1 × origin + 1
1.699 × 10¹⁰⁰(101-digit number)
16992003970785260650…86059420170862607961
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
3.398 × 10¹⁰⁰(101-digit number)
33984007941570521301…72118840341725215919
Verify on FactorDB ↗Wolfram Alpha ↗
2^2 × origin + 1
3.398 × 10¹⁰⁰(101-digit number)
33984007941570521301…72118840341725215921
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
6.796 × 10¹⁰⁰(101-digit number)
67968015883141042602…44237680683450431839
Verify on FactorDB ↗Wolfram Alpha ↗
2^3 × origin + 1
6.796 × 10¹⁰⁰(101-digit number)
67968015883141042602…44237680683450431841
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
1.359 × 10¹⁰¹(102-digit number)
13593603176628208520…88475361366900863679
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:57,676,673 XPM·at block #6,804,077 · updates every 60s
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