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Home/Chain Registry/Block #2,260,394

Block #2,260,394

1CCLength 12β˜…β˜…β˜…β˜…β˜†

Cunningham Chain of the First Kind Β· Discovered 8/20/2017, 4:44:30 PM Β· Difficulty 10.9519 Β· 4,573,513 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
2c8dcb8aefe16a540634a7905de69a4a7e681a7c76fd5b48d9192b8ff569130c
View on Chainz β†—

Difficulty

10.951862

Transactions

1

Size

200 B

Version

2

Bits

0af3ad3a

Nonce

763,347,495

Timestamp

8/20/2017, 4:44:30 PM

Confirmations

4,573,513

Merkle Root

0a2db571b48140b0b7b2be4123c56f5450c93cb2df7e0db50fc8f8cfe41b9563
Transactions (1)
Coinbase0a2db571b48140…c8f8cfe41b9563
1 in β†’ 1 out8.3200 XPM110 B
AWskBWLF…VhXrHgV8
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.

9.812 Γ— 10⁹⁴(95-digit number)
98129596741814704637…19349692850042279120
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
9.812 Γ— 10⁹⁴(95-digit number)
98129596741814704637…19349692850042279119
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2+1 β†’
2
2^1 Γ— origin βˆ’ 1
1.962 Γ— 10⁹⁡(96-digit number)
19625919348362940927…38699385700084558239
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2+1 β†’
3
2^2 Γ— origin βˆ’ 1
3.925 Γ— 10⁹⁡(96-digit number)
39251838696725881855…77398771400169116479
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2+1 β†’
4
2^3 Γ— origin βˆ’ 1
7.850 Γ— 10⁹⁡(96-digit number)
78503677393451763710…54797542800338232959
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2+1 β†’
5
2^4 Γ— origin βˆ’ 1
1.570 Γ— 10⁹⁢(97-digit number)
15700735478690352742…09595085600676465919
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2+1 β†’
6
2^5 Γ— origin βˆ’ 1
3.140 Γ— 10⁹⁢(97-digit number)
31401470957380705484…19190171201352931839
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2+1 β†’
7
2^6 Γ— origin βˆ’ 1
6.280 Γ— 10⁹⁢(97-digit number)
62802941914761410968…38380342402705863679
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2+1 β†’
8
2^7 Γ— origin βˆ’ 1
1.256 Γ— 10⁹⁷(98-digit number)
12560588382952282193…76760684805411727359
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2+1 β†’
9
2^8 Γ— origin βˆ’ 1
2.512 Γ— 10⁹⁷(98-digit number)
25121176765904564387…53521369610823454719
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2+1 β†’
10
2^9 Γ— origin βˆ’ 1
5.024 Γ— 10⁹⁷(98-digit number)
50242353531809128774…07042739221646909439
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2+1 β†’
11
2^10 Γ— origin βˆ’ 1
1.004 Γ— 10⁹⁸(99-digit number)
10048470706361825754…14085478443293818879
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2+1 β†’
12
2^11 Γ— origin βˆ’ 1
2.009 Γ— 10⁹⁸(99-digit number)
20096941412723651509…28170956886587637759
Verify on FactorDB β†—Wolfram Alpha β†—

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 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
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 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 2260394

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 2c8dcb8aefe16a540634a7905de69a4a7e681a7c76fd5b48d9192b8ff569130c

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 #2,260,394 on Chainz β†—
Circulating Supply:57,915,480 XPMΒ·at block #6,833,906 Β· updates every 60s
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