Home/Chain Registry/Block #273,106

Block #273,106

1CCLength 9★☆☆☆☆

Cunningham Chain of the First Kind · Discovered 11/25/2013, 3:21:31 PM · Difficulty 9.9541 · 6,525,273 confirmations

1CC
Cunningham Chain of the First Kind

A sequence where each prime is double the previous prime plus one.

Block Header
Block Hash
d1db8b3894f2675a431df45286bd995f7cb2d9e52fbb7e48a437b2f5de111b92

Height

#273,106

Difficulty

9.954112

Transactions

8

Size

9.67 KB

Version

2

Bits

09f440ad

Nonce

281,432

Timestamp

11/25/2013, 3:21:31 PM

Confirmations

6,525,273

Merkle Root

11f53280d50a217a4e1522851765ced110d77b37dc37c6cfd18aa9aedd8af6ce
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.

2.016 × 10⁸⁹(90-digit number)
20160436680491882996…85068630274745964720
Discovered Prime Numbers
p_k = 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.

1
origin − 1
2.016 × 10⁸⁹(90-digit number)
20160436680491882996…85068630274745964719
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
4.032 × 10⁸⁹(90-digit number)
40320873360983765992…70137260549491929439
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
8.064 × 10⁸⁹(90-digit number)
80641746721967531985…40274521098983858879
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
1.612 × 10⁹⁰(91-digit number)
16128349344393506397…80549042197967717759
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
3.225 × 10⁹⁰(91-digit number)
32256698688787012794…61098084395935435519
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
6.451 × 10⁹⁰(91-digit number)
64513397377574025588…22196168791870871039
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
1.290 × 10⁹¹(92-digit number)
12902679475514805117…44392337583741742079
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
2.580 × 10⁹¹(92-digit number)
25805358951029610235…88784675167483484159
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
5.161 × 10⁹¹(92-digit number)
51610717902059220470…77569350334966968319
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 Cunningham Chain of the First Kind. 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 1CC formula:

1CC: p₁ (first prime), p₂ = 2p₁ + 1, p₃ = 2p₂ + 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 273106

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 d1db8b3894f2675a431df45286bd995f7cb2d9e52fbb7e48a437b2f5de111b92

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 #273,106 on Chainz ↗
Circulating Supply:57,631,038 XPM·at block #6,798,378 · updates every 60s
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