Block #349,641

TWNLength 12★★★★☆

Bi-Twin Chain · Discovered 1/8/2014, 1:16:25 PM · Difficulty 10.2770 · 6,454,136 confirmations

TWN
Bi-Twin Chain

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

Block Header
Block Hash
3ad43775fac3119056a58e1b07bf522f9943f7aea4730ae36616e644df4aa29c

Height

#349,641

Difficulty

10.277041

Transactions

8

Size

2.95 KB

Version

2

Bits

0a46ec22

Nonce

139,435

Timestamp

1/8/2014, 1:16:25 PM

Confirmations

6,454,136

Merkle Root

010830fb996c6573b2c568263e0303c81b6a599c1ff10bca4b4fe6bee6675f42
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.

5.842 × 10⁹⁶(97-digit number)
58426817019731832766…44419785603685884889
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
5.842 × 10⁹⁶(97-digit number)
58426817019731832766…44419785603685884889
Verify on FactorDB ↗Wolfram Alpha ↗
origin + 1
5.842 × 10⁹⁶(97-digit number)
58426817019731832766…44419785603685884891
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
1.168 × 10⁹⁷(98-digit number)
11685363403946366553…88839571207371769779
Verify on FactorDB ↗Wolfram Alpha ↗
2^1 × origin + 1
1.168 × 10⁹⁷(98-digit number)
11685363403946366553…88839571207371769781
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
2.337 × 10⁹⁷(98-digit number)
23370726807892733106…77679142414743539559
Verify on FactorDB ↗Wolfram Alpha ↗
2^2 × origin + 1
2.337 × 10⁹⁷(98-digit number)
23370726807892733106…77679142414743539561
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
4.674 × 10⁹⁷(98-digit number)
46741453615785466213…55358284829487079119
Verify on FactorDB ↗Wolfram Alpha ↗
2^3 × origin + 1
4.674 × 10⁹⁷(98-digit number)
46741453615785466213…55358284829487079121
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
9.348 × 10⁹⁷(98-digit number)
93482907231570932426…10716569658974158239
Verify on FactorDB ↗Wolfram Alpha ↗
2^4 × origin + 1
9.348 × 10⁹⁷(98-digit number)
93482907231570932426…10716569658974158241
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
1.869 × 10⁹⁸(99-digit number)
18696581446314186485…21433139317948316479
Verify on FactorDB ↗Wolfram Alpha ↗
2^5 × origin + 1
1.869 × 10⁹⁸(99-digit number)
18696581446314186485…21433139317948316481
Verify on FactorDB ↗Wolfram Alpha ↗
Difference: 2^5 × origin + 1 − 2^5 × origin − 1 = 2 (twin primes ✓)

What this block proved

The miner who found this block proved the existence of 12 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
ExceptionalChain length 12

Around 1 in 10,000 blocks. A significant mathematical achievement.

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:57,674,255 XPM·at block #6,803,776 · updates every 60s
xpmprime.info is a work in progress. If you enjoy using this service you can support this project with a Primecoin donation.