Home/Chain Registry/Block #461,526

Block #461,526

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 3/26/2014, 7:17:22 PM · Difficulty 10.4140 · 6,329,927 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
c2137117a5461581956d2e7d964f0a75f99b84c6a4ddbcb6a3b79303087c3d6f

Height

#461,526

Difficulty

10.413998

Transactions

9

Size

2.05 KB

Version

2

Bits

0a69fbcc

Nonce

143,037

Timestamp

3/26/2014, 7:17:22 PM

Confirmations

6,329,927

Merkle Root

1dcfc798f8fd6cef3a6eb661a82c220b88ae896d53c20d12fb51705bc5548676
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.

5.255 × 10¹⁰³(104-digit number)
52551122182532654200…93557869885371174400
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
5.255 × 10¹⁰³(104-digit number)
52551122182532654200…93557869885371174401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
1.051 × 10¹⁰⁴(105-digit number)
10510224436506530840…87115739770742348801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
2.102 × 10¹⁰⁴(105-digit number)
21020448873013061680…74231479541484697601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
4.204 × 10¹⁰⁴(105-digit number)
42040897746026123360…48462959082969395201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
8.408 × 10¹⁰⁴(105-digit number)
84081795492052246721…96925918165938790401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
1.681 × 10¹⁰⁵(106-digit number)
16816359098410449344…93851836331877580801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
3.363 × 10¹⁰⁵(106-digit number)
33632718196820898688…87703672663755161601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
6.726 × 10¹⁰⁵(106-digit number)
67265436393641797376…75407345327510323201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
1.345 × 10¹⁰⁶(107-digit number)
13453087278728359475…50814690655020646401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
2.690 × 10¹⁰⁶(107-digit number)
26906174557456718950…01629381310041292801
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 461526

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 c2137117a5461581956d2e7d964f0a75f99b84c6a4ddbcb6a3b79303087c3d6f

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 #461,526 on Chainz ↗
Circulating Supply:57,575,566 XPM·at block #6,791,452 · updates every 60s
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