Home/Chain Registry/Block #3,504,861

Block #3,504,861

1CCLength 11★★★☆☆

Cunningham Chain of the First Kind · Discovered 1/8/2020, 5:25:09 AM · Difficulty 10.9306 · 3,340,788 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
adf73429b0edca25b0ad1bd22c36547a90b5d503217cba028937c0550f45968c

Difficulty

10.930621

Transactions

11

Size

72.88 KB

Version

2

Bits

0aee3d2a

Nonce

1,631,536,726

Timestamp

1/8/2020, 5:25:09 AM

Confirmations

3,340,788

Merkle Root

80cc94f3a7d6c117fce21d41baa2cca049493795e8e05f25515cc028b862cdf6
Transactions (11)
1 in → 1 out9.1600 XPM109 B
50 in → 1 out199.9200 XPM7.26 KB
50 in → 1 out199.9200 XPM7.26 KB
50 in → 1 out199.9200 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
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.

3.387 × 10⁹²(93-digit number)
33878638091366270996…21806266687707718240
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
3.387 × 10⁹²(93-digit number)
33878638091366270996…21806266687707718239
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
6.775 × 10⁹²(93-digit number)
67757276182732541992…43612533375415436479
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
1.355 × 10⁹³(94-digit number)
13551455236546508398…87225066750830872959
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
2.710 × 10⁹³(94-digit number)
27102910473093016796…74450133501661745919
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
5.420 × 10⁹³(94-digit number)
54205820946186033593…48900267003323491839
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
1.084 × 10⁹⁴(95-digit number)
10841164189237206718…97800534006646983679
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
2.168 × 10⁹⁴(95-digit number)
21682328378474413437…95601068013293967359
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
4.336 × 10⁹⁴(95-digit number)
43364656756948826875…91202136026587934719
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
8.672 × 10⁹⁴(95-digit number)
86729313513897653750…82404272053175869439
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
1.734 × 10⁹⁵(96-digit number)
17345862702779530750…64808544106351738879
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
11
2^10 × origin − 1
3.469 × 10⁹⁵(96-digit number)
34691725405559061500…29617088212703477759
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 3504861

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 adf73429b0edca25b0ad1bd22c36547a90b5d503217cba028937c0550f45968c

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 #3,504,861 on Chainz ↗
Circulating Supply:58,009,641 XPM·at block #6,845,648 · updates every 60s
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