Home/Chain Registry/Block #295,200

Block #295,200

TWNLength 9★☆☆☆☆

Bi-Twin Chain · Discovered 12/5/2013, 7:38:09 AM · Difficulty 9.9913 · 6,496,724 confirmations

TWN
Bi-Twin Chain

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

Block Header
Block Hash
7a3cef07b1093ec9ac7900bae7f324c6e50327a2ccca53d5cc4f7e7d06c26341

Height

#295,200

Difficulty

9.991291

Transactions

9

Size

40.71 KB

Version

2

Bits

09fdc540

Nonce

311

Timestamp

12/5/2013, 7:38:09 AM

Confirmations

6,496,724

Merkle Root

9d47d9d5a25b319156280619bd6d345f9a0af7bda7e943629e0879f3ff6162cf
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.

6.340 × 10⁹²(93-digit number)
63404699611492972343…13014133732689261600
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
6.340 × 10⁹²(93-digit number)
63404699611492972343…13014133732689261599
Verify on FactorDB ↗Wolfram Alpha ↗
origin + 1
6.340 × 10⁹²(93-digit number)
63404699611492972343…13014133732689261601
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
1.268 × 10⁹³(94-digit number)
12680939922298594468…26028267465378523199
Verify on FactorDB ↗Wolfram Alpha ↗
2^1 × origin + 1
1.268 × 10⁹³(94-digit number)
12680939922298594468…26028267465378523201
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
2.536 × 10⁹³(94-digit number)
25361879844597188937…52056534930757046399
Verify on FactorDB ↗Wolfram Alpha ↗
2^2 × origin + 1
2.536 × 10⁹³(94-digit number)
25361879844597188937…52056534930757046401
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
5.072 × 10⁹³(94-digit number)
50723759689194377874…04113069861514092799
Verify on FactorDB ↗Wolfram Alpha ↗
2^3 × origin + 1
5.072 × 10⁹³(94-digit number)
50723759689194377874…04113069861514092801
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
1.014 × 10⁹⁴(95-digit number)
10144751937838875574…08226139723028185599
Verify on FactorDB ↗Wolfram Alpha ↗

What this block proved

The miner who found this block proved the existence of 9 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.

View full Prime Chain Discovery page →
★☆☆☆☆
Rarity
CommonChain length 9
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
Verify on a Primecoin Node

Anyone running a Primecoin node can independently verify this block using the following RPC commands. Run these from the primecoin-cli command line or via the debug console in the Primecoin wallet.

1. Get block hash by height
getblockhash 295200

Returns the block hash for a given block height. Use this to confirm the hash shown above matches the chain.

2. Get full block data
getblock 7a3cef07b1093ec9ac7900bae7f324c6e50327a2ccca53d5cc4f7e7d06c26341

Returns the full block header including difficulty, prime chain origin, prime chain type, transaction IDs, and all other fields shown on this page.

How to run these commands: To verify this data independently, open a terminal on your own Primecoin node and run primecoin-cli <command>. Alternatively, open the Primecoin-Qt wallet, go to Help → Debug Window → Console, and type the command directly. The node must be fully synced to this block height for the commands to return results.

Cross-reference on Chainz Explorer

Chainz is an independent Primecoin block explorer. Compare this block's data to verify accuracy.

View Block #295,200 on Chainz ↗
Circulating Supply:57,579,346 XPM·at block #6,791,923 · updates every 60s
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