Block #929,140

TWNLength 11★★★☆☆

Bi-Twin Chain · Discovered 2/9/2015, 2:16:15 PM · Difficulty 10.9039 · 5,876,915 confirmations

TWN
Bi-Twin Chain

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

Block Header
Block Hash
f3ce3583601730cf477425cd3caf1414bdb0ef5b77536a95fbee6e93296b491a

Height

#929,140

Difficulty

10.903910

Transactions

5

Size

1.01 KB

Version

2

Bits

0ae766ac

Nonce

76,393,439

Timestamp

2/9/2015, 2:16:15 PM

Confirmations

5,876,915

Merkle Root

33e474f60d9c21eeb9865988814be7cdb4b9fdde77a8e3f8d8e8c2f72d08594f
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.

1.698 × 10⁹⁴(95-digit number)
16980520246473430225…14090889401509854359
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
1.698 × 10⁹⁴(95-digit number)
16980520246473430225…14090889401509854359
Verify on FactorDB ↗Wolfram Alpha ↗
origin + 1
1.698 × 10⁹⁴(95-digit number)
16980520246473430225…14090889401509854361
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
3.396 × 10⁹⁴(95-digit number)
33961040492946860451…28181778803019708719
Verify on FactorDB ↗Wolfram Alpha ↗
2^1 × origin + 1
3.396 × 10⁹⁴(95-digit number)
33961040492946860451…28181778803019708721
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
6.792 × 10⁹⁴(95-digit number)
67922080985893720902…56363557606039417439
Verify on FactorDB ↗Wolfram Alpha ↗
2^2 × origin + 1
6.792 × 10⁹⁴(95-digit number)
67922080985893720902…56363557606039417441
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
1.358 × 10⁹⁵(96-digit number)
13584416197178744180…12727115212078834879
Verify on FactorDB ↗Wolfram Alpha ↗
2^3 × origin + 1
1.358 × 10⁹⁵(96-digit number)
13584416197178744180…12727115212078834881
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
2.716 × 10⁹⁵(96-digit number)
27168832394357488361…25454230424157669759
Verify on FactorDB ↗Wolfram Alpha ↗
2^4 × origin + 1
2.716 × 10⁹⁵(96-digit number)
27168832394357488361…25454230424157669761
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
5.433 × 10⁹⁵(96-digit number)
54337664788714976722…50908460848315339519
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:57,692,523 XPM·at block #6,806,054 · updates every 60s
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