Home/Chain Registry/Block #253,095

Block #253,095

TWNLength 9★☆☆☆☆

Bi-Twin Chain · Discovered 11/9/2013, 10:55:36 PM · Difficulty 9.9719 · 6,538,775 confirmations

TWN
Bi-Twin Chain

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

Block Header
Block Hash
ce2cb27be652adc4ff6f7f701bcd2a6f8f6febae172265abb8064ebe4c30b4b8

Height

#253,095

Difficulty

9.971946

Transactions

6

Size

1.47 KB

Version

2

Bits

09f8d16d

Nonce

15,563

Timestamp

11/9/2013, 10:55:36 PM

Confirmations

6,538,775

Merkle Root

a51ec3df2b75afcd111ce1cac0be75e0a6cab1305805801195b0b562ab21dd54
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.

4.790 × 10⁹⁴(95-digit number)
47908232188759320600…14852973612576712800
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
4.790 × 10⁹⁴(95-digit number)
47908232188759320600…14852973612576712799
Verify on FactorDB ↗Wolfram Alpha ↗
origin + 1
4.790 × 10⁹⁴(95-digit number)
47908232188759320600…14852973612576712801
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
9.581 × 10⁹⁴(95-digit number)
95816464377518641201…29705947225153425599
Verify on FactorDB ↗Wolfram Alpha ↗
2^1 × origin + 1
9.581 × 10⁹⁴(95-digit number)
95816464377518641201…29705947225153425601
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
1.916 × 10⁹⁵(96-digit number)
19163292875503728240…59411894450306851199
Verify on FactorDB ↗Wolfram Alpha ↗
2^2 × origin + 1
1.916 × 10⁹⁵(96-digit number)
19163292875503728240…59411894450306851201
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
3.832 × 10⁹⁵(96-digit number)
38326585751007456480…18823788900613702399
Verify on FactorDB ↗Wolfram Alpha ↗
2^3 × origin + 1
3.832 × 10⁹⁵(96-digit number)
38326585751007456480…18823788900613702401
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
7.665 × 10⁹⁵(96-digit number)
76653171502014912961…37647577801227404799
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 253095

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 ce2cb27be652adc4ff6f7f701bcd2a6f8f6febae172265abb8064ebe4c30b4b8

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 #253,095 on Chainz ↗
Circulating Supply:57,578,916 XPM·at block #6,791,869 · updates every 60s
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