Block #156,294

TWNLength 10★★☆☆☆

Bi-Twin Chain · Discovered 9/8/2013, 8:52:11 PM · Difficulty 9.8681 · 6,638,658 confirmations

TWN
Bi-Twin Chain

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

Block Header
Block Hash
f34a47ae724d5d5df6912e17dd1759317fcc36b9435a2cef77b3c1668cf6e950

Height

#156,294

Difficulty

9.868141

Transactions

9

Size

3.30 KB

Version

2

Bits

09de3e7d

Nonce

48,767

Timestamp

9/8/2013, 8:52:11 PM

Confirmations

6,638,658

Merkle Root

a9028dc0afc45e9e4a4c5eba16acbf8ba103ed956f623cba2b34212bbe556227
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.

4.662 × 10⁹³(94-digit number)
46622716043762345560…21993607354525377279
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
4.662 × 10⁹³(94-digit number)
46622716043762345560…21993607354525377279
Verify on FactorDB ↗Wolfram Alpha ↗
origin + 1
4.662 × 10⁹³(94-digit number)
46622716043762345560…21993607354525377281
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
9.324 × 10⁹³(94-digit number)
93245432087524691120…43987214709050754559
Verify on FactorDB ↗Wolfram Alpha ↗
2^1 × origin + 1
9.324 × 10⁹³(94-digit number)
93245432087524691120…43987214709050754561
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
1.864 × 10⁹⁴(95-digit number)
18649086417504938224…87974429418101509119
Verify on FactorDB ↗Wolfram Alpha ↗
2^2 × origin + 1
1.864 × 10⁹⁴(95-digit number)
18649086417504938224…87974429418101509121
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
3.729 × 10⁹⁴(95-digit number)
37298172835009876448…75948858836203018239
Verify on FactorDB ↗Wolfram Alpha ↗
2^3 × origin + 1
3.729 × 10⁹⁴(95-digit number)
37298172835009876448…75948858836203018241
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
7.459 × 10⁹⁴(95-digit number)
74596345670019752896…51897717672406036479
Verify on FactorDB ↗Wolfram Alpha ↗
2^4 × origin + 1
7.459 × 10⁹⁴(95-digit number)
74596345670019752896…51897717672406036481
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:57,603,652 XPM·at block #6,794,951 · updates every 60s
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