Home/Chain Registry/Block #2,995,768

Block #2,995,768

1CCLength 11★★★☆☆

Cunningham Chain of the First Kind · Discovered 1/4/2019, 8:35:16 PM · Difficulty 11.2641 · 3,846,577 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
32ca55a2043ab98ee074136adfd79e0fe70bd8c6fc36b57a0313b6b99b3c557a

Difficulty

11.264063

Transactions

5

Size

2.01 KB

Version

2

Bits

0b4399a6

Nonce

1,875,246,138

Timestamp

1/4/2019, 8:35:16 PM

Confirmations

3,846,577

Merkle Root

5b2f8d5187f08788d2356dd89c6c739f5d54548b7ededef966c7d0ff2bf18887
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.

2.500 × 10⁹⁷(98-digit number)
25006441590661637182…80169042505841095680
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
2.500 × 10⁹⁷(98-digit number)
25006441590661637182…80169042505841095679
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
5.001 × 10⁹⁷(98-digit number)
50012883181323274365…60338085011682191359
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
1.000 × 10⁹⁸(99-digit number)
10002576636264654873…20676170023364382719
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
2.000 × 10⁹⁸(99-digit number)
20005153272529309746…41352340046728765439
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
4.001 × 10⁹⁸(99-digit number)
40010306545058619492…82704680093457530879
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
8.002 × 10⁹⁸(99-digit number)
80020613090117238984…65409360186915061759
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
1.600 × 10⁹⁹(100-digit number)
16004122618023447796…30818720373830123519
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
3.200 × 10⁹⁹(100-digit number)
32008245236046895593…61637440747660247039
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
6.401 × 10⁹⁹(100-digit number)
64016490472093791187…23274881495320494079
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
1.280 × 10¹⁰⁰(101-digit number)
12803298094418758237…46549762990640988159
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
11
2^10 × origin − 1
2.560 × 10¹⁰⁰(101-digit number)
25606596188837516474…93099525981281976319
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 2995768

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 32ca55a2043ab98ee074136adfd79e0fe70bd8c6fc36b57a0313b6b99b3c557a

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 #2,995,768 on Chainz ↗
Circulating Supply:57,983,167 XPM·at block #6,842,344 · updates every 60s
xpmprime.info is a work in progress. If you enjoy using this service you can support this project with a Primecoin donation.
Privacy Policy·

Cookie Preferences

We use cookies to enhance your experience. Some are essential for the site to function, while others help us understand how you use the site.

·Privacy Policy