Home/Chain Registry/Block #83,752

Block #83,752

1CCLength 9★☆☆☆☆

Cunningham Chain of the First Kind · Discovered 7/26/2013, 8:49:47 AM · Difficulty 9.2707 · 6,733,036 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
d2b8741bddd0abd47e45023cdcb5049b850c92a39e2d8e710b7647c288aa659e

Height

#83,752

Difficulty

9.270743

Transactions

6

Size

1.42 KB

Version

2

Bits

09454f6b

Nonce

6,552

Timestamp

7/26/2013, 8:49:47 AM

Confirmations

6,733,036

Merkle Root

95982e38936c2dc743928d020466be9fd70861001db1fb60b48c9537c5ed94ac
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.

1.016 × 10¹¹⁹(120-digit number)
10160948168182600155…80491077939049846640
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
1.016 × 10¹¹⁹(120-digit number)
10160948168182600155…80491077939049846639
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
2.032 × 10¹¹⁹(120-digit number)
20321896336365200310…60982155878099693279
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
4.064 × 10¹¹⁹(120-digit number)
40643792672730400620…21964311756199386559
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
8.128 × 10¹¹⁹(120-digit number)
81287585345460801241…43928623512398773119
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
1.625 × 10¹²⁰(121-digit number)
16257517069092160248…87857247024797546239
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
3.251 × 10¹²⁰(121-digit number)
32515034138184320496…75714494049595092479
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
6.503 × 10¹²⁰(121-digit number)
65030068276368640993…51428988099190184959
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
1.300 × 10¹²¹(122-digit number)
13006013655273728198…02857976198380369919
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
2.601 × 10¹²¹(122-digit number)
26012027310547456397…05715952396760739839
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 83752

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 d2b8741bddd0abd47e45023cdcb5049b850c92a39e2d8e710b7647c288aa659e

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 #83,752 on Chainz ↗
Circulating Supply:57,778,339 XPM·at block #6,816,787 · updates every 60s
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