Home/Chain Registry/Block #78,458

Block #78,458

1CCLength 9★☆☆☆☆

Cunningham Chain of the First Kind · Discovered 7/22/2013, 10:04:01 PM · Difficulty 9.2205 · 6,721,587 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
50096e2fb557637d91f6df2ed42e0d283618814c4c5e5bcfd3065908231620c3

Height

#78,458

Difficulty

9.220546

Transactions

6

Size

3.12 KB

Version

2

Bits

093875ad

Nonce

1,214

Timestamp

7/22/2013, 10:04:01 PM

Confirmations

6,721,587

Merkle Root

d8187bf8326b7e9ce889331ca1ce36427a67f7e6135adabc9a6b59802b4274ba
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.

7.950 × 10¹¹¹(112-digit number)
79507840664413738960…72329285243189220510
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
7.950 × 10¹¹¹(112-digit number)
79507840664413738960…72329285243189220509
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
1.590 × 10¹¹²(113-digit number)
15901568132882747792…44658570486378441019
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
3.180 × 10¹¹²(113-digit number)
31803136265765495584…89317140972756882039
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
6.360 × 10¹¹²(113-digit number)
63606272531530991168…78634281945513764079
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
1.272 × 10¹¹³(114-digit number)
12721254506306198233…57268563891027528159
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
2.544 × 10¹¹³(114-digit number)
25442509012612396467…14537127782055056319
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
5.088 × 10¹¹³(114-digit number)
50885018025224792934…29074255564110112639
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
1.017 × 10¹¹⁴(115-digit number)
10177003605044958586…58148511128220225279
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
2.035 × 10¹¹⁴(115-digit number)
20354007210089917173…16297022256440450559
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 78458

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 50096e2fb557637d91f6df2ed42e0d283618814c4c5e5bcfd3065908231620c3

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 #78,458 on Chainz ↗
Circulating Supply:57,644,420 XPM·at block #6,800,044 · updates every 60s
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