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Home/Chain Registry/Block #2,924,928

Block #2,924,928

2CCLength 11β˜…β˜…β˜…β˜†β˜†

Cunningham Chain of the Second Kind Β· Discovered 11/16/2018, 4:20:58 AM Β· Difficulty 11.3559 Β· 3,916,522 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
ee9c0f4264a50d3ea1fcc5ec074a183df5a9efcd5d4974fd9650667e728e02ad
View on Chainz β†—

Difficulty

11.355853

Transactions

1

Size

200 B

Version

2

Bits

0b5b1935

Nonce

174,320,337

Timestamp

11/16/2018, 4:20:58 AM

Confirmations

3,916,522

Merkle Root

271bbb9cbf3545cf6a3646253ad179aa7627b80eed704fab1b00ba0c647c0935
Transactions (1)
Coinbase271bbb9cbf3545…00ba0c647c0935
1 in β†’ 1 out7.7400 XPM109 B
AUhjokok…k5m93PZR
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.

1.273 Γ— 10⁹⁷(98-digit number)
12736092718287992717…60308857069622712320
Discovered Prime Numbers
p_k = 2^k Γ— 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
1.273 Γ— 10⁹⁷(98-digit number)
12736092718287992717…60308857069622712321
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
2
2^1 Γ— origin + 1
2.547 Γ— 10⁹⁷(98-digit number)
25472185436575985434…20617714139245424641
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
3
2^2 Γ— origin + 1
5.094 Γ— 10⁹⁷(98-digit number)
50944370873151970869…41235428278490849281
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
4
2^3 Γ— origin + 1
1.018 Γ— 10⁹⁸(99-digit number)
10188874174630394173…82470856556981698561
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
5
2^4 Γ— origin + 1
2.037 Γ— 10⁹⁸(99-digit number)
20377748349260788347…64941713113963397121
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
6
2^5 Γ— origin + 1
4.075 Γ— 10⁹⁸(99-digit number)
40755496698521576695…29883426227926794241
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
7
2^6 Γ— origin + 1
8.151 Γ— 10⁹⁸(99-digit number)
81510993397043153391…59766852455853588481
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
8
2^7 Γ— origin + 1
1.630 Γ— 10⁹⁹(100-digit number)
16302198679408630678…19533704911707176961
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
9
2^8 Γ— origin + 1
3.260 Γ— 10⁹⁹(100-digit number)
32604397358817261356…39067409823414353921
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
10
2^9 Γ— origin + 1
6.520 Γ— 10⁹⁹(100-digit number)
65208794717634522713…78134819646828707841
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
11
2^10 Γ— origin + 1
1.304 Γ— 10¹⁰⁰(101-digit number)
13041758943526904542…56269639293657415681
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 Second 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 2CC formula:

2CC: p₁ (first prime), pβ‚‚ = 2p₁ βˆ’ 1, p₃ = 2pβ‚‚ βˆ’ 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 2924928

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 ee9c0f4264a50d3ea1fcc5ec074a183df5a9efcd5d4974fd9650667e728e02ad

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 #2,924,928 on Chainz β†—
Circulating Supply:57,975,979 XPMΒ·at block #6,841,449 Β· updates every 60s
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