Home/Chain Registry/Block #497,626

Block #497,626

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 4/17/2014, 4:45:13 PM · Difficulty 10.7698 · 6,312,262 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
35bbd176b2096af29c740fcdb8df4e115cde3f9bdb4d6cbf1c19126bb060329b

Height

#497,626

Difficulty

10.769791

Transactions

10

Size

2.66 KB

Version

2

Bits

0ac5110a

Nonce

282,278,896

Timestamp

4/17/2014, 4:45:13 PM

Confirmations

6,312,262

Merkle Root

9ac966f4daa109912f10e615cc8578d7ff61e76b0742519907394c28b1f55a15
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.

3.017 × 10⁹⁸(99-digit number)
30171654964388733374…04977064587301328800
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
3.017 × 10⁹⁸(99-digit number)
30171654964388733374…04977064587301328801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
6.034 × 10⁹⁸(99-digit number)
60343309928777466749…09954129174602657601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
1.206 × 10⁹⁹(100-digit number)
12068661985755493349…19908258349205315201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
2.413 × 10⁹⁹(100-digit number)
24137323971510986699…39816516698410630401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
4.827 × 10⁹⁹(100-digit number)
48274647943021973399…79633033396821260801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
9.654 × 10⁹⁹(100-digit number)
96549295886043946799…59266066793642521601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
1.930 × 10¹⁰⁰(101-digit number)
19309859177208789359…18532133587285043201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
3.861 × 10¹⁰⁰(101-digit number)
38619718354417578719…37064267174570086401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
7.723 × 10¹⁰⁰(101-digit number)
77239436708835157439…74128534349140172801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
1.544 × 10¹⁰¹(102-digit number)
15447887341767031487…48257068698280345601
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 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
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 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 497626

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 35bbd176b2096af29c740fcdb8df4e115cde3f9bdb4d6cbf1c19126bb060329b

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 #497,626 on Chainz ↗
Circulating Supply:57,723,192 XPM·at block #6,809,887 · updates every 60s
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