Home/Chain Registry/Block #303,614

Block #303,614

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 12/10/2013, 11:38:06 AM · Difficulty 9.9931 · 6,508,897 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
ad31412f4f399e352fd75d435ceca699b299f01aba34565caf7e4b38e8337463

Height

#303,614

Difficulty

9.993066

Transactions

28

Size

8.97 KB

Version

2

Bits

09fe3996

Nonce

34,835

Timestamp

12/10/2013, 11:38:06 AM

Confirmations

6,508,897

Merkle Root

376fb2f4370ab184620e91d81213bcc9ed62dbb7a76a8837a132648e882e958e
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.

8.900 × 10⁹¹(92-digit number)
89001383374889219393…50651924187138194040
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
8.900 × 10⁹¹(92-digit number)
89001383374889219393…50651924187138194039
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
1.780 × 10⁹²(93-digit number)
17800276674977843878…01303848374276388079
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
3.560 × 10⁹²(93-digit number)
35600553349955687757…02607696748552776159
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
7.120 × 10⁹²(93-digit number)
71201106699911375514…05215393497105552319
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
1.424 × 10⁹³(94-digit number)
14240221339982275102…10430786994211104639
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
2.848 × 10⁹³(94-digit number)
28480442679964550205…20861573988422209279
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
5.696 × 10⁹³(94-digit number)
56960885359929100411…41723147976844418559
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
1.139 × 10⁹⁴(95-digit number)
11392177071985820082…83446295953688837119
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
2.278 × 10⁹⁴(95-digit number)
22784354143971640164…66892591907377674239
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
4.556 × 10⁹⁴(95-digit number)
45568708287943280329…33785183814755348479
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 303614

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 ad31412f4f399e352fd75d435ceca699b299f01aba34565caf7e4b38e8337463

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 #303,614 on Chainz ↗
Circulating Supply:57,744,121 XPM·at block #6,812,510 · updates every 60s
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