Home/Chain Registry/Block #513,392

Block #513,392

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 4/27/2014, 12:13:27 PM · Difficulty 10.8350 · 6,329,288 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
8653ad921b25deb2fbee3ce2a6fcbe8bfdd63f261292b201e2fab860bce24a5b

Height

#513,392

Difficulty

10.835010

Transactions

15

Size

3.86 KB

Version

2

Bits

0ad5c336

Nonce

1,243,093,304

Timestamp

4/27/2014, 12:13:27 PM

Confirmations

6,329,288

Merkle Root

740aa531879df9eea0e5cd6e561c26d1f20a29709109387e14688a63557d81c3
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.

6.801 × 10⁸⁹(90-digit number)
68010406280511278425…33239559879959779880
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
6.801 × 10⁸⁹(90-digit number)
68010406280511278425…33239559879959779881
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
1.360 × 10⁹⁰(91-digit number)
13602081256102255685…66479119759919559761
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
2.720 × 10⁹⁰(91-digit number)
27204162512204511370…32958239519839119521
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
5.440 × 10⁹⁰(91-digit number)
54408325024409022740…65916479039678239041
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
1.088 × 10⁹¹(92-digit number)
10881665004881804548…31832958079356478081
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
2.176 × 10⁹¹(92-digit number)
21763330009763609096…63665916158712956161
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
4.352 × 10⁹¹(92-digit number)
43526660019527218192…27331832317425912321
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
8.705 × 10⁹¹(92-digit number)
87053320039054436384…54663664634851824641
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
1.741 × 10⁹²(93-digit number)
17410664007810887276…09327329269703649281
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
3.482 × 10⁹²(93-digit number)
34821328015621774553…18654658539407298561
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 513392

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 8653ad921b25deb2fbee3ce2a6fcbe8bfdd63f261292b201e2fab860bce24a5b

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 #513,392 on Chainz ↗
Circulating Supply:57,985,876 XPM·at block #6,842,679 · updates every 60s
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