Home/Chain Registry/Block #212,279

Block #212,279

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 10/16/2013, 4:48:54 AM · Difficulty 9.9186 · 6,612,432 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
6509c2daed5f632e43f28aa3e866b36c51acc1ee2cc31e36ffe08edc8a1ea6b1

Height

#212,279

Difficulty

9.918612

Transactions

6

Size

2.42 KB

Version

2

Bits

09eb2a2b

Nonce

325,701

Timestamp

10/16/2013, 4:48:54 AM

Confirmations

6,612,432

Merkle Root

22403fda50c8bfa5d0e35e2516a136e1a71ea89a6f367aa2c4236ee5b84fce95
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.

5.148 × 10⁹³(94-digit number)
51488169714796917417…27676897933916307960
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
5.148 × 10⁹³(94-digit number)
51488169714796917417…27676897933916307959
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
1.029 × 10⁹⁴(95-digit number)
10297633942959383483…55353795867832615919
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
2.059 × 10⁹⁴(95-digit number)
20595267885918766967…10707591735665231839
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
4.119 × 10⁹⁴(95-digit number)
41190535771837533934…21415183471330463679
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
8.238 × 10⁹⁴(95-digit number)
82381071543675067868…42830366942660927359
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
1.647 × 10⁹⁵(96-digit number)
16476214308735013573…85660733885321854719
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
3.295 × 10⁹⁵(96-digit number)
32952428617470027147…71321467770643709439
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
6.590 × 10⁹⁵(96-digit number)
65904857234940054294…42642935541287418879
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
1.318 × 10⁹⁶(97-digit number)
13180971446988010858…85285871082574837759
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
2.636 × 10⁹⁶(97-digit number)
26361942893976021717…70571742165149675519
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 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
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 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 212279

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 6509c2daed5f632e43f28aa3e866b36c51acc1ee2cc31e36ffe08edc8a1ea6b1

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 #212,279 on Chainz ↗
Circulating Supply:57,841,754 XPM·at block #6,824,710 · updates every 60s
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