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Home/Chain Registry/Block #2,930,055

Block #2,930,055

2CCLength 11β˜…β˜…β˜…β˜†β˜†

Cunningham Chain of the Second Kind Β· Discovered 11/19/2018, 1:23:37 PM Β· Difficulty 11.3890 Β· 3,910,736 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
f61cd6aa579672659d2852018cfecbde385e0e2384cfd132ecdc8ab02873bc35
View on Chainz β†—

Difficulty

11.388952

Transactions

1

Size

199 B

Version

2

Bits

0b639256

Nonce

1,400,179,123

Timestamp

11/19/2018, 1:23:37 PM

Confirmations

3,910,736

Merkle Root

7377ed57d43393c4bf6a22076becabea48ddce6f5acc2030c980d7715bf43b19
Transactions (1)
Coinbase7377ed57d43393…80d7715bf43b19
1 in β†’ 1 out7.7000 XPM110 B
AbXwmGxD…4XXYP765
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.

1.491 Γ— 10⁹³(94-digit number)
14914398629083983768…55666879495098672000
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
1.491 Γ— 10⁹³(94-digit number)
14914398629083983768…55666879495098672001
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
2
2^1 Γ— origin + 1
2.982 Γ— 10⁹³(94-digit number)
29828797258167967536…11333758990197344001
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
3
2^2 Γ— origin + 1
5.965 Γ— 10⁹³(94-digit number)
59657594516335935072…22667517980394688001
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
4
2^3 Γ— origin + 1
1.193 Γ— 10⁹⁴(95-digit number)
11931518903267187014…45335035960789376001
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
5
2^4 Γ— origin + 1
2.386 Γ— 10⁹⁴(95-digit number)
23863037806534374028…90670071921578752001
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
6
2^5 Γ— origin + 1
4.772 Γ— 10⁹⁴(95-digit number)
47726075613068748057…81340143843157504001
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
7
2^6 Γ— origin + 1
9.545 Γ— 10⁹⁴(95-digit number)
95452151226137496115…62680287686315008001
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
8
2^7 Γ— origin + 1
1.909 Γ— 10⁹⁡(96-digit number)
19090430245227499223…25360575372630016001
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
9
2^8 Γ— origin + 1
3.818 Γ— 10⁹⁡(96-digit number)
38180860490454998446…50721150745260032001
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
10
2^9 Γ— origin + 1
7.636 Γ— 10⁹⁡(96-digit number)
76361720980909996892…01442301490520064001
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
11
2^10 Γ— origin + 1
1.527 Γ— 10⁹⁢(97-digit number)
15272344196181999378…02884602981040128001
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 2930055

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 f61cd6aa579672659d2852018cfecbde385e0e2384cfd132ecdc8ab02873bc35

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 #2,930,055 on Chainz β†—
Circulating Supply:57,970,675 XPMΒ·at block #6,840,790 Β· updates every 60s
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