Home/Chain Registry/Block #234,236

Block #234,236

2CCLength 9★☆☆☆☆

Cunningham Chain of the Second Kind · Discovered 10/30/2013, 5:18:54 AM · Difficulty 9.9436 · 6,566,148 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
6f12ca0fa50294b1ff26cb673e6723ebe45011017de423ce63c6a3a7c8176062

Height

#234,236

Difficulty

9.943623

Transactions

5

Size

2.20 KB

Version

2

Bits

09f1914a

Nonce

128,524

Timestamp

10/30/2013, 5:18:54 AM

Confirmations

6,566,148

Merkle Root

d1b8916fd4e0c78b0fe7e18b7e0640d1cdedf40620afbe3b9559ff52030e8464
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.

1.759 × 10⁹²(93-digit number)
17591239981037098235…26420386238047761480
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
1.759 × 10⁹²(93-digit number)
17591239981037098235…26420386238047761481
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
3.518 × 10⁹²(93-digit number)
35182479962074196471…52840772476095522961
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
7.036 × 10⁹²(93-digit number)
70364959924148392943…05681544952191045921
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
1.407 × 10⁹³(94-digit number)
14072991984829678588…11363089904382091841
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
2.814 × 10⁹³(94-digit number)
28145983969659357177…22726179808764183681
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
5.629 × 10⁹³(94-digit number)
56291967939318714354…45452359617528367361
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
1.125 × 10⁹⁴(95-digit number)
11258393587863742870…90904719235056734721
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
2.251 × 10⁹⁴(95-digit number)
22516787175727485741…81809438470113469441
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
4.503 × 10⁹⁴(95-digit number)
45033574351454971483…63618876940226938881
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 Second 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 2CC formula:

2CC: 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 234236

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 6f12ca0fa50294b1ff26cb673e6723ebe45011017de423ce63c6a3a7c8176062

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 #234,236 on Chainz ↗
Circulating Supply:57,647,132 XPM·at block #6,800,383 · updates every 60s
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