Home/Chain Registry/Block #301,632

Block #301,632

2CCLength 9★☆☆☆☆

Cunningham Chain of the Second Kind · Discovered 12/9/2013, 8:14:28 AM · Difficulty 9.9925 · 6,523,938 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
0c7d9619f08802b2019d48e4794c944dcb0bbe2d757d2221f7a092b12bd4b70a

Height

#301,632

Difficulty

9.992519

Transactions

7

Size

10.63 KB

Version

2

Bits

09fe15bc

Nonce

2,225

Timestamp

12/9/2013, 8:14:28 AM

Confirmations

6,523,938

Merkle Root

9a59db181b45e0589a6210a3b0c0f4099bdbabd1a237a7dd8a214c1571f64cac
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.

1.760 × 10⁹⁶(97-digit number)
17603475284807423506…92696788808590132160
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
1.760 × 10⁹⁶(97-digit number)
17603475284807423506…92696788808590132161
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
3.520 × 10⁹⁶(97-digit number)
35206950569614847012…85393577617180264321
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
7.041 × 10⁹⁶(97-digit number)
70413901139229694025…70787155234360528641
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
1.408 × 10⁹⁷(98-digit number)
14082780227845938805…41574310468721057281
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
2.816 × 10⁹⁷(98-digit number)
28165560455691877610…83148620937442114561
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
5.633 × 10⁹⁷(98-digit number)
56331120911383755220…66297241874884229121
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
1.126 × 10⁹⁸(99-digit number)
11266224182276751044…32594483749768458241
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
2.253 × 10⁹⁸(99-digit number)
22532448364553502088…65188967499536916481
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
4.506 × 10⁹⁸(99-digit number)
45064896729107004176…30377934999073832961
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 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
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 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 301632

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 0c7d9619f08802b2019d48e4794c944dcb0bbe2d757d2221f7a092b12bd4b70a

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 #301,632 on Chainz ↗
Circulating Supply:57,848,661 XPM·at block #6,825,569 · updates every 60s
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