Home/Chain Registry/Block #3,503,555

Block #3,503,555

1CCLength 11★★★☆☆

Cunningham Chain of the First Kind · Discovered 1/7/2020, 7:18:48 AM · Difficulty 10.9308 · 3,339,167 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
db5befab9be065d3c7746c8c8ce45df04861f06cf429304c376920a03d470330

Difficulty

10.930825

Transactions

10

Size

65.62 KB

Version

2

Bits

0aee4a8e

Nonce

382,529,136

Timestamp

1/7/2020, 7:18:48 AM

Confirmations

3,339,167

Merkle Root

647f89a932ac95b97cf478457685601389e1328acfff325e5ae990150b937a52
Transactions (10)
1 in → 1 out9.0800 XPM109 B
50 in → 1 out399.9200 XPM7.27 KB
50 in → 1 out399.9200 XPM7.28 KB
50 in → 1 out399.9200 XPM7.26 KB
50 in → 1 out399.9200 XPM7.27 KB
50 in → 1 out399.9200 XPM7.26 KB
50 in → 1 out399.9200 XPM7.27 KB
50 in → 1 out399.9200 XPM7.27 KB
50 in → 1 out399.9200 XPM7.27 KB
50 in → 1 out3927.2000 XPM7.27 KB
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.

4.693 × 10⁹⁷(98-digit number)
46938585626558975920…88337513238325749760
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
4.693 × 10⁹⁷(98-digit number)
46938585626558975920…88337513238325749759
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
9.387 × 10⁹⁷(98-digit number)
93877171253117951841…76675026476651499519
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
1.877 × 10⁹⁸(99-digit number)
18775434250623590368…53350052953302999039
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
3.755 × 10⁹⁸(99-digit number)
37550868501247180736…06700105906605998079
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
7.510 × 10⁹⁸(99-digit number)
75101737002494361473…13400211813211996159
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
1.502 × 10⁹⁹(100-digit number)
15020347400498872294…26800423626423992319
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
3.004 × 10⁹⁹(100-digit number)
30040694800997744589…53600847252847984639
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
6.008 × 10⁹⁹(100-digit number)
60081389601995489178…07201694505695969279
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
1.201 × 10¹⁰⁰(101-digit number)
12016277920399097835…14403389011391938559
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
2.403 × 10¹⁰⁰(101-digit number)
24032555840798195671…28806778022783877119
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
11
2^10 × origin − 1
4.806 × 10¹⁰⁰(101-digit number)
48065111681596391343…57613556045567754239
Verify on FactorDB ↗Wolfram Alpha ↗

What this block proved

The miner who found this block proved the existence of 11 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
RareChain length 11
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 3503555

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 db5befab9be065d3c7746c8c8ce45df04861f06cf429304c376920a03d470330

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 #3,503,555 on Chainz ↗
Circulating Supply:57,986,114 XPM·at block #6,842,721 · updates every 60s
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