Home/Chain Registry/Block #3,504,191

Block #3,504,191

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 1/7/2020, 5:50:06 PM · Difficulty 10.9309 · 3,336,599 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
efe9ed4b3dae2064a4bbf995e3591e1ae0310d7fb35b3efa99d786e28fdd03a7

Difficulty

10.930917

Transactions

11

Size

72.88 KB

Version

2

Bits

0aee508f

Nonce

1,761,711,807

Timestamp

1/7/2020, 5:50:06 PM

Confirmations

3,336,599

Merkle Root

30e8acf1317f77c6b496e05381f9243676f951573fd3ee33285aeeedabb64c99
Transactions (11)
1 in → 1 out9.1600 XPM110 B
50 in → 1 out200.5400 XPM7.27 KB
50 in → 1 out200.5251 XPM7.27 KB
50 in → 1 out200.5227 XPM7.27 KB
50 in → 1 out200.5357 XPM7.26 KB
50 in → 1 out200.5381 XPM7.26 KB
50 in → 1 out200.5332 XPM7.26 KB
50 in → 1 out6689.3537 XPM7.26 KB
50 in → 1 out200.5280 XPM7.27 KB
50 in → 1 out200.5426 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.

3.067 × 10⁹⁵(96-digit number)
30678992666159212589…75663291848498442240
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
3.067 × 10⁹⁵(96-digit number)
30678992666159212589…75663291848498442239
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
6.135 × 10⁹⁵(96-digit number)
61357985332318425179…51326583696996884479
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
1.227 × 10⁹⁶(97-digit number)
12271597066463685035…02653167393993768959
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
2.454 × 10⁹⁶(97-digit number)
24543194132927370071…05306334787987537919
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
4.908 × 10⁹⁶(97-digit number)
49086388265854740143…10612669575975075839
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
9.817 × 10⁹⁶(97-digit number)
98172776531709480287…21225339151950151679
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
1.963 × 10⁹⁷(98-digit number)
19634555306341896057…42450678303900303359
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
3.926 × 10⁹⁷(98-digit number)
39269110612683792115…84901356607800606719
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
7.853 × 10⁹⁷(98-digit number)
78538221225367584230…69802713215601213439
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
1.570 × 10⁹⁸(99-digit number)
15707644245073516846…39605426431202426879
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 3504191

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 efe9ed4b3dae2064a4bbf995e3591e1ae0310d7fb35b3efa99d786e28fdd03a7

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 #3,504,191 on Chainz ↗
Circulating Supply:57,970,667 XPM·at block #6,840,789 · updates every 60s
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