Home/Chain Registry/Block #346,909

Block #346,909

TWNLength 10★★☆☆☆

Bi-Twin Chain · Discovered 1/6/2014, 8:22:58 PM · Difficulty 10.2356 · 6,447,916 confirmations

TWN
Bi-Twin Chain

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

Block Header
Block Hash
7da2e5428103fbbfa87797f340e5b633a41b64ecdcb7fb1c6050de1b2e49283d

Height

#346,909

Difficulty

10.235574

Transactions

17

Size

4.47 KB

Version

2

Bits

0a3c4e98

Nonce

164,956

Timestamp

1/6/2014, 8:22:58 PM

Confirmations

6,447,916

Merkle Root

3a604443ef9c75df347f76f9b712f0823ae27d116cbb142cf1efb146864c6f8d
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.

3.806 × 10¹⁰³(104-digit number)
38066150582028066922…44373922678688030720
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
3.806 × 10¹⁰³(104-digit number)
38066150582028066922…44373922678688030719
Verify on FactorDB ↗Wolfram Alpha ↗
origin + 1
3.806 × 10¹⁰³(104-digit number)
38066150582028066922…44373922678688030721
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
7.613 × 10¹⁰³(104-digit number)
76132301164056133844…88747845357376061439
Verify on FactorDB ↗Wolfram Alpha ↗
2^1 × origin + 1
7.613 × 10¹⁰³(104-digit number)
76132301164056133844…88747845357376061441
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
1.522 × 10¹⁰⁴(105-digit number)
15226460232811226768…77495690714752122879
Verify on FactorDB ↗Wolfram Alpha ↗
2^2 × origin + 1
1.522 × 10¹⁰⁴(105-digit number)
15226460232811226768…77495690714752122881
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
3.045 × 10¹⁰⁴(105-digit number)
30452920465622453537…54991381429504245759
Verify on FactorDB ↗Wolfram Alpha ↗
2^3 × origin + 1
3.045 × 10¹⁰⁴(105-digit number)
30452920465622453537…54991381429504245761
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
6.090 × 10¹⁰⁴(105-digit number)
60905840931244907075…09982762859008491519
Verify on FactorDB ↗Wolfram Alpha ↗
2^4 × origin + 1
6.090 × 10¹⁰⁴(105-digit number)
60905840931244907075…09982762859008491521
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.

View full Prime Chain Discovery page →
★★☆☆☆
Rarity
UncommonChain length 10
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 346909

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 7da2e5428103fbbfa87797f340e5b633a41b64ecdcb7fb1c6050de1b2e49283d

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 #346,909 on Chainz ↗
Circulating Supply:57,602,648 XPM·at block #6,794,824 · updates every 60s
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