Home/Chain Registry/Block #294,909

Block #294,909

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 12/5/2013, 3:45:33 AM · Difficulty 9.9912 · 6,549,926 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
b532940e67877e6f886ef358fa3a2f368736896f0d4cb6b731f15ada2c416ef1

Height

#294,909

Difficulty

9.991176

Transactions

5

Size

2.26 KB

Version

2

Bits

09fdbdb4

Nonce

35,229

Timestamp

12/5/2013, 3:45:33 AM

Confirmations

6,549,926

Merkle Root

945ca897c5471b850504d7ed1af776d961217b8b25e4396f1bdc58627c2ac813
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.

1.053 × 10⁹⁶(97-digit number)
10530502310545068334…65739786998380843840
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
1.053 × 10⁹⁶(97-digit number)
10530502310545068334…65739786998380843839
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
2.106 × 10⁹⁶(97-digit number)
21061004621090136668…31479573996761687679
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
4.212 × 10⁹⁶(97-digit number)
42122009242180273336…62959147993523375359
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
8.424 × 10⁹⁶(97-digit number)
84244018484360546672…25918295987046750719
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
1.684 × 10⁹⁷(98-digit number)
16848803696872109334…51836591974093501439
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
3.369 × 10⁹⁷(98-digit number)
33697607393744218668…03673183948187002879
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
6.739 × 10⁹⁷(98-digit number)
67395214787488437337…07346367896374005759
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
1.347 × 10⁹⁸(99-digit number)
13479042957497687467…14692735792748011519
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
2.695 × 10⁹⁸(99-digit number)
26958085914995374935…29385471585496023039
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
5.391 × 10⁹⁸(99-digit number)
53916171829990749870…58770943170992046079
Verify on FactorDB ↗Wolfram Alpha ↗

What this block proved

The miner who found this block proved the existence of 10 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
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 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 294909

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 b532940e67877e6f886ef358fa3a2f368736896f0d4cb6b731f15ada2c416ef1

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 #294,909 on Chainz ↗
Circulating Supply:58,003,088 XPM·at block #6,844,834 · updates every 60s
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