Home/Chain Registry/Block #2,911,576

Block #2,911,576

1CCLength 11β˜…β˜…β˜…β˜†β˜†

Cunningham Chain of the First Kind Β· Discovered 11/5/2018, 8:25:15 PM Β· Difficulty 11.5234 Β· 3,933,254 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
c74294aec4e8fd0a78e956e5780d88016078797780d331668058b2c10719fad6

Difficulty

11.523449

Transactions

1

Size

201 B

Version

2

Bits

0b8600c8

Nonce

1,205,142,762

Timestamp

11/5/2018, 8:25:15 PM

Confirmations

3,933,254

Merkle Root

c6723abb95bb14870b2286d6b0ed466c5861f51e9628306e6edca5a1ca166cda
Transactions (1)
1 in β†’ 1 out7.5200 XPM110 B
Prime Chain Origin

This is the prime chain origin stored in the block header. It is a composite number (not prime itself) β€” it equals the first prime in the chain multiplied by a primorial. The origin anchors the entire chain to this specific block.

2.867 Γ— 10⁹⁢(97-digit number)
28678210394682019713…84350304167700449280
Discovered Prime Numbers
p_k = 2^k Γ— origin βˆ’ 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 βˆ’ 1
2.867 Γ— 10⁹⁢(97-digit number)
28678210394682019713…84350304167700449279
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2+1 β†’
2
2^1 Γ— origin βˆ’ 1
5.735 Γ— 10⁹⁢(97-digit number)
57356420789364039426…68700608335400898559
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2+1 β†’
3
2^2 Γ— origin βˆ’ 1
1.147 Γ— 10⁹⁷(98-digit number)
11471284157872807885…37401216670801797119
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2+1 β†’
4
2^3 Γ— origin βˆ’ 1
2.294 Γ— 10⁹⁷(98-digit number)
22942568315745615770…74802433341603594239
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2+1 β†’
5
2^4 Γ— origin βˆ’ 1
4.588 Γ— 10⁹⁷(98-digit number)
45885136631491231541…49604866683207188479
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2+1 β†’
6
2^5 Γ— origin βˆ’ 1
9.177 Γ— 10⁹⁷(98-digit number)
91770273262982463082…99209733366414376959
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2+1 β†’
7
2^6 Γ— origin βˆ’ 1
1.835 Γ— 10⁹⁸(99-digit number)
18354054652596492616…98419466732828753919
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2+1 β†’
8
2^7 Γ— origin βˆ’ 1
3.670 Γ— 10⁹⁸(99-digit number)
36708109305192985232…96838933465657507839
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2+1 β†’
9
2^8 Γ— origin βˆ’ 1
7.341 Γ— 10⁹⁸(99-digit number)
73416218610385970465…93677866931315015679
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2+1 β†’
10
2^9 Γ— origin βˆ’ 1
1.468 Γ— 10⁹⁹(100-digit number)
14683243722077194093…87355733862630031359
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2+1 β†’
11
2^10 Γ— origin βˆ’ 1
2.936 Γ— 10⁹⁹(100-digit number)
29366487444154388186…74711467725260062719
Verify on FactorDB β†—Wolfram Alpha β†—

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 β€” the large number shown above β€” 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 β†’
β˜…β˜…β˜…β˜†β˜†
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 Γ— 3 Γ— 5 Γ— 7 Γ— …), the result is the first prime in the chain. The origin is deliberately divisible by this primorial β€” that divisibility is part of the proof.

Prime Chain Origin = First Prime Γ— Primorial (2Β·3Β·5Β·7Β·11·…)
Source: Primecoin prime.cpp β€” CheckPrimeProofOfWork()

This is why the origin has many small prime factors β€” those factors are the primorial divisor. The chain then extends from the first prime using the 1CC formula:

1CC: p₁ (first prime), pβ‚‚ = 2p₁ + 1, p₃ = 2pβ‚‚ + 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 2911576

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 c74294aec4e8fd0a78e956e5780d88016078797780d331668058b2c10719fad6

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 β†’ Debug Window β†’ 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 #2,911,576 on Chainz β†—
Circulating Supply:58,003,049 XPMΒ·at block #6,844,829 Β· updates every 60s
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