Block #835,974

TWNLength 11★★★☆☆

Bi-Twin Chain · Discovered 12/1/2014, 6:13:09 PM · Difficulty 10.9763 · 5,962,595 confirmations

TWN
Bi-Twin Chain

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

Block Header
Block Hash
7e7f73bce2be83ab40d4664dca8377df80115fa049f75ee4f1ee40acc85b5f40

Height

#835,974

Difficulty

10.976284

Transactions

9

Size

2.83 KB

Version

2

Bits

0af9edb8

Nonce

1,660,672,332

Timestamp

12/1/2014, 6:13:09 PM

Confirmations

5,962,595

Merkle Root

4d9fde9432562211a8154e884d1d8052b69baf9566e255bdbbf59ab3c646aecd
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.

2.280 × 10⁹⁴(95-digit number)
22800235797400022482…73131706299896499799
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
2.280 × 10⁹⁴(95-digit number)
22800235797400022482…73131706299896499799
Verify on FactorDB ↗Wolfram Alpha ↗
origin + 1
2.280 × 10⁹⁴(95-digit number)
22800235797400022482…73131706299896499801
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
4.560 × 10⁹⁴(95-digit number)
45600471594800044965…46263412599792999599
Verify on FactorDB ↗Wolfram Alpha ↗
2^1 × origin + 1
4.560 × 10⁹⁴(95-digit number)
45600471594800044965…46263412599792999601
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
9.120 × 10⁹⁴(95-digit number)
91200943189600089930…92526825199585999199
Verify on FactorDB ↗Wolfram Alpha ↗
2^2 × origin + 1
9.120 × 10⁹⁴(95-digit number)
91200943189600089930…92526825199585999201
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
1.824 × 10⁹⁵(96-digit number)
18240188637920017986…85053650399171998399
Verify on FactorDB ↗Wolfram Alpha ↗
2^3 × origin + 1
1.824 × 10⁹⁵(96-digit number)
18240188637920017986…85053650399171998401
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
3.648 × 10⁹⁵(96-digit number)
36480377275840035972…70107300798343996799
Verify on FactorDB ↗Wolfram Alpha ↗
2^4 × origin + 1
3.648 × 10⁹⁵(96-digit number)
36480377275840035972…70107300798343996801
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
7.296 × 10⁹⁵(96-digit number)
72960754551680071944…40214601596687993599
Verify on FactorDB ↗Wolfram Alpha ↗

What this block proved

The miner who found this block proved the existence of 11 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
RareChain length 11

Approximately 1 in 1,000 blocks. Noteworthy discoveries.

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:57,632,570 XPM·at block #6,798,568 · updates every 60s
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