Block #29,820

TWNLength 7★☆☆☆☆

Bi-Twin Chain · Discovered 7/13/2013, 4:51:34 PM · Difficulty 7.9855 · 6,765,032 confirmations

TWN
Bi-Twin Chain

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

Block Header
Block Hash
ec43ce9e80f1bd2053b1b555429e893b361f9986f724b5e785a33969c9b6cbae

Height

#29,820

Difficulty

7.985529

Transactions

12

Size

10.40 KB

Version

2

Bits

07fc4ba1

Nonce

1

Timestamp

7/13/2013, 4:51:34 PM

Confirmations

6,765,032

Merkle Root

c358ceecd4437fcf6ca72b4b2cd809ebbdef81ac626fc54b8feb50a85035e929
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.

1.106 × 10¹¹¹(112-digit number)
11062792331876281509…36632157572849442189
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
1.106 × 10¹¹¹(112-digit number)
11062792331876281509…36632157572849442189
Verify on FactorDB ↗Wolfram Alpha ↗
origin + 1
1.106 × 10¹¹¹(112-digit number)
11062792331876281509…36632157572849442191
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
2.212 × 10¹¹¹(112-digit number)
22125584663752563018…73264315145698884379
Verify on FactorDB ↗Wolfram Alpha ↗
2^1 × origin + 1
2.212 × 10¹¹¹(112-digit number)
22125584663752563018…73264315145698884381
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
4.425 × 10¹¹¹(112-digit number)
44251169327505126036…46528630291397768759
Verify on FactorDB ↗Wolfram Alpha ↗
2^2 × origin + 1
4.425 × 10¹¹¹(112-digit number)
44251169327505126036…46528630291397768761
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
8.850 × 10¹¹¹(112-digit number)
88502338655010252073…93057260582795537519
Verify on FactorDB ↗Wolfram Alpha ↗

What this block proved

The miner who found this block proved the existence of 7 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 7

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:57,602,845 XPM·at block #6,794,851 · 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.