Home/Chain Registry/Block #3,503,304

Block #3,503,304

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 1/7/2020, 3:22:00 AM · Difficulty 10.9306 · 3,338,868 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
d0f9e62a661117148dff423bbd9c85c1bf759f07ce5dd9e70cfd1d7c9d852cd5

Difficulty

10.930648

Transactions

11

Size

72.91 KB

Version

2

Bits

0aee3eed

Nonce

1,499,756,583

Timestamp

1/7/2020, 3:22:00 AM

Confirmations

3,338,868

Merkle Root

9aac112e8cc184977317ec7525e080595f0699c4ede08cbe49eb3289f8f99170
Transactions (11)
1 in → 1 out9.1600 XPM109 B
50 in → 1 out599.9200 XPM7.27 KB
50 in → 1 out599.9200 XPM7.27 KB
50 in → 1 out599.9200 XPM7.27 KB
50 in → 1 out599.9200 XPM7.27 KB
50 in → 1 out599.9200 XPM7.27 KB
50 in → 1 out599.9200 XPM7.27 KB
50 in → 1 out599.9200 XPM7.27 KB
50 in → 1 out599.9200 XPM7.27 KB
50 in → 1 out599.9200 XPM7.28 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.

1.081 × 10⁹⁷(98-digit number)
10819469921088170029…42752623295500165120
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
1.081 × 10⁹⁷(98-digit number)
10819469921088170029…42752623295500165119
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
2.163 × 10⁹⁷(98-digit number)
21638939842176340058…85505246591000330239
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
4.327 × 10⁹⁷(98-digit number)
43277879684352680116…71010493182000660479
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
8.655 × 10⁹⁷(98-digit number)
86555759368705360232…42020986364001320959
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
1.731 × 10⁹⁸(99-digit number)
17311151873741072046…84041972728002641919
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
3.462 × 10⁹⁸(99-digit number)
34622303747482144093…68083945456005283839
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
6.924 × 10⁹⁸(99-digit number)
69244607494964288186…36167890912010567679
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
1.384 × 10⁹⁹(100-digit number)
13848921498992857637…72335781824021135359
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
2.769 × 10⁹⁹(100-digit number)
27697842997985715274…44671563648042270719
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
5.539 × 10⁹⁹(100-digit number)
55395685995971430549…89343127296084541439
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 3503304

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 d0f9e62a661117148dff423bbd9c85c1bf759f07ce5dd9e70cfd1d7c9d852cd5

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 #3,503,304 on Chainz ↗
Circulating Supply:57,981,766 XPM·at block #6,842,171 · updates every 60s
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