Block #292,219

TWNLength 9★☆☆☆☆

Bi-Twin Chain · Discovered 12/3/2013, 2:54:57 PM · Difficulty 9.9902 · 6,502,774 confirmations

TWN
Bi-Twin Chain

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

Block Header
Block Hash
8f7bb1dbaf8268013d7b597ad8b9cdddece5ee7b83b4711220ecc8495a212b7d

Height

#292,219

Difficulty

9.990205

Transactions

7

Size

3.51 KB

Version

2

Bits

09fd7e18

Nonce

365,743

Timestamp

12/3/2013, 2:54:57 PM

Confirmations

6,502,774

Merkle Root

6b8b898225b2d10fa3c7ce5240a006d8ddc44d461c3c34260029a22f612eb24d
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.

9.164 × 10⁹⁴(95-digit number)
91649208254050198862…93081277789650435959
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
9.164 × 10⁹⁴(95-digit number)
91649208254050198862…93081277789650435959
Verify on FactorDB ↗Wolfram Alpha ↗
origin + 1
9.164 × 10⁹⁴(95-digit number)
91649208254050198862…93081277789650435961
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
1.832 × 10⁹⁵(96-digit number)
18329841650810039772…86162555579300871919
Verify on FactorDB ↗Wolfram Alpha ↗
2^1 × origin + 1
1.832 × 10⁹⁵(96-digit number)
18329841650810039772…86162555579300871921
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
3.665 × 10⁹⁵(96-digit number)
36659683301620079545…72325111158601743839
Verify on FactorDB ↗Wolfram Alpha ↗
2^2 × origin + 1
3.665 × 10⁹⁵(96-digit number)
36659683301620079545…72325111158601743841
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
7.331 × 10⁹⁵(96-digit number)
73319366603240159090…44650222317203487679
Verify on FactorDB ↗Wolfram Alpha ↗
2^3 × origin + 1
7.331 × 10⁹⁵(96-digit number)
73319366603240159090…44650222317203487681
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
1.466 × 10⁹⁶(97-digit number)
14663873320648031818…89300444634406975359
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:57,603,986 XPM·at block #6,794,992 · updates every 60s
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