Home/Chain Registry/Block #437,764

Block #437,764

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 3/10/2014, 12:37:43 PM · Difficulty 10.3600 · 6,362,962 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
c67e69238aa5b0dfc4380adac37edfe17a4680da0ed0def1fb83431e942a4aa7

Height

#437,764

Difficulty

10.359957

Transactions

5

Size

1.08 KB

Version

2

Bits

0a5c262b

Nonce

117,515

Timestamp

3/10/2014, 12:37:43 PM

Confirmations

6,362,962

Merkle Root

07070c78defc07bb9e840f955b9de31b247521a61fa270025c765440ea80f6e2
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.

4.618 × 10⁹⁶(97-digit number)
46182814297255938714…74534004222213917120
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
4.618 × 10⁹⁶(97-digit number)
46182814297255938714…74534004222213917121
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
9.236 × 10⁹⁶(97-digit number)
92365628594511877428…49068008444427834241
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
1.847 × 10⁹⁷(98-digit number)
18473125718902375485…98136016888855668481
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
3.694 × 10⁹⁷(98-digit number)
36946251437804750971…96272033777711336961
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
7.389 × 10⁹⁷(98-digit number)
73892502875609501942…92544067555422673921
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
1.477 × 10⁹⁸(99-digit number)
14778500575121900388…85088135110845347841
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
2.955 × 10⁹⁸(99-digit number)
29557001150243800777…70176270221690695681
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
5.911 × 10⁹⁸(99-digit number)
59114002300487601554…40352540443381391361
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
1.182 × 10⁹⁹(100-digit number)
11822800460097520310…80705080886762782721
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
2.364 × 10⁹⁹(100-digit number)
23645600920195040621…61410161773525565441
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 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
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 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 437764

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 c67e69238aa5b0dfc4380adac37edfe17a4680da0ed0def1fb83431e942a4aa7

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 #437,764 on Chainz ↗
Circulating Supply:57,649,877 XPM·at block #6,800,725 · updates every 60s
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