Home/Chain Registry/Block #3,505,332

Block #3,505,332

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 1/8/2020, 1:17:06 PM · Difficulty 10.9306 · 3,326,864 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
a1f694cce95598ac95563fb6cbddf3eb7af071b469d4a9636d4f17a6c0ae2108

Difficulty

10.930612

Transactions

12

Size

73.66 KB

Version

2

Bits

0aee3c97

Nonce

1,710,973,580

Timestamp

1/8/2020, 1:17:06 PM

Confirmations

3,326,864

Merkle Root

3c93d15a93137f813cc09da959d8d0ba8d0f92c37fe14a43855109097991d647
Transactions (12)
1 in → 1 out9.1700 XPM109 B
50 in → 1 out199.9200 XPM7.27 KB
50 in → 1 out199.9200 XPM7.27 KB
50 in → 1 out199.9200 XPM7.28 KB
50 in → 1 out199.9200 XPM7.27 KB
50 in → 1 out1963.2000 XPM7.26 KB
50 in → 1 out199.9200 XPM7.27 KB
50 in → 1 out199.9200 XPM7.27 KB
50 in → 1 out199.9200 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.

6.154 × 10⁹⁶(97-digit number)
61540468162585871677…92594181935052180480
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
6.154 × 10⁹⁶(97-digit number)
61540468162585871677…92594181935052180479
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
1.230 × 10⁹⁷(98-digit number)
12308093632517174335…85188363870104360959
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
2.461 × 10⁹⁷(98-digit number)
24616187265034348671…70376727740208721919
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
4.923 × 10⁹⁷(98-digit number)
49232374530068697342…40753455480417443839
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
9.846 × 10⁹⁷(98-digit number)
98464749060137394684…81506910960834887679
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
1.969 × 10⁹⁸(99-digit number)
19692949812027478936…63013821921669775359
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
3.938 × 10⁹⁸(99-digit number)
39385899624054957873…26027643843339550719
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
7.877 × 10⁹⁸(99-digit number)
78771799248109915747…52055287686679101439
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
1.575 × 10⁹⁹(100-digit number)
15754359849621983149…04110575373358202879
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
3.150 × 10⁹⁹(100-digit number)
31508719699243966299…08221150746716405759
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 3505332

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 a1f694cce95598ac95563fb6cbddf3eb7af071b469d4a9636d4f17a6c0ae2108

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 #3,505,332 on Chainz ↗
Circulating Supply:57,901,701 XPM·at block #6,832,195 · updates every 60s
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