Home/Chain Registry/Block #2,950,483

Block #2,950,483

1CCLength 12★★★★☆

Cunningham Chain of the First Kind · Discovered 12/3/2018, 4:53:17 PM · Difficulty 11.3971 · 3,882,567 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
dc4d4e0500b13809a337beb6afb9d28bb7d0aa6d2096ba4cf4ff66d94aa8572f

Difficulty

11.397146

Transactions

33

Size

8.29 KB

Version

2

Bits

0b65ab57

Nonce

660,506,177

Timestamp

12/3/2018, 4:53:17 PM

Confirmations

3,882,567

Merkle Root

18cbb2b4090b4970ac03937d9d88299a4e0ab6b081b2170caa42619003589397
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.

2.260 × 10⁹⁴(95-digit number)
22607453068086363806…94126249063021748720
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
2.260 × 10⁹⁴(95-digit number)
22607453068086363806…94126249063021748719
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
4.521 × 10⁹⁴(95-digit number)
45214906136172727612…88252498126043497439
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
9.042 × 10⁹⁴(95-digit number)
90429812272345455224…76504996252086994879
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
1.808 × 10⁹⁵(96-digit number)
18085962454469091044…53009992504173989759
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
3.617 × 10⁹⁵(96-digit number)
36171924908938182089…06019985008347979519
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
7.234 × 10⁹⁵(96-digit number)
72343849817876364179…12039970016695959039
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
1.446 × 10⁹⁶(97-digit number)
14468769963575272835…24079940033391918079
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
2.893 × 10⁹⁶(97-digit number)
28937539927150545671…48159880066783836159
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
5.787 × 10⁹⁶(97-digit number)
57875079854301091343…96319760133567672319
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
1.157 × 10⁹⁷(98-digit number)
11575015970860218268…92639520267135344639
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
11
2^10 × origin − 1
2.315 × 10⁹⁷(98-digit number)
23150031941720436537…85279040534270689279
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
12
2^11 × origin − 1
4.630 × 10⁹⁷(98-digit number)
46300063883440873074…70558081068541378559
Verify on FactorDB ↗Wolfram Alpha ↗

What this block proved

The miner who found this block proved the existence of 12 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
ExceptionalChain length 12
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 2950483

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 dc4d4e0500b13809a337beb6afb9d28bb7d0aa6d2096ba4cf4ff66d94aa8572f

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 #2,950,483 on Chainz ↗
Circulating Supply:57,908,580 XPM·at block #6,833,049 · updates every 60s
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