Block #1,626,557

TWNLength 10★★☆☆☆

Bi-Twin Chain · Discovered 6/13/2016, 12:36:27 PM · Difficulty 10.5869 · 5,179,551 confirmations

TWN
Bi-Twin Chain

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

Block Header
Block Hash
bdbc47bf22a35f8714035707610f12ccba02619043a6965275e9386a78c91d47

Height

#1,626,557

Difficulty

10.586919

Transactions

4

Size

5.74 KB

Version

2

Bits

0a964056

Nonce

8,469,374

Timestamp

6/13/2016, 12:36:27 PM

Confirmations

5,179,551

Merkle Root

86ebd22970603870f8f66946ce1289b9fcccda9c63fd4f5c9dd62e09ef8ca616
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.

2.017 × 10⁹⁷(98-digit number)
20177978922767466904…76103458944687800319
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
2.017 × 10⁹⁷(98-digit number)
20177978922767466904…76103458944687800319
Verify on FactorDB ↗Wolfram Alpha ↗
origin + 1
2.017 × 10⁹⁷(98-digit number)
20177978922767466904…76103458944687800321
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
4.035 × 10⁹⁷(98-digit number)
40355957845534933809…52206917889375600639
Verify on FactorDB ↗Wolfram Alpha ↗
2^1 × origin + 1
4.035 × 10⁹⁷(98-digit number)
40355957845534933809…52206917889375600641
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
8.071 × 10⁹⁷(98-digit number)
80711915691069867618…04413835778751201279
Verify on FactorDB ↗Wolfram Alpha ↗
2^2 × origin + 1
8.071 × 10⁹⁷(98-digit number)
80711915691069867618…04413835778751201281
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
1.614 × 10⁹⁸(99-digit number)
16142383138213973523…08827671557502402559
Verify on FactorDB ↗Wolfram Alpha ↗
2^3 × origin + 1
1.614 × 10⁹⁸(99-digit number)
16142383138213973523…08827671557502402561
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
3.228 × 10⁹⁸(99-digit number)
32284766276427947047…17655343115004805119
Verify on FactorDB ↗Wolfram Alpha ↗
2^4 × origin + 1
3.228 × 10⁹⁸(99-digit number)
32284766276427947047…17655343115004805121
Verify on FactorDB ↗Wolfram Alpha ↗
Difference: 2^4 × origin + 1 − 2^4 × origin − 1 = 2 (twin primes ✓)

What this block proved

The miner who found this block proved the existence of 10 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
UncommonChain length 10

Roughly 1 in 100 blocks. Solid but expected in a healthy network.

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:57,692,939 XPM·at block #6,806,107 · updates every 60s
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