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Home/Chain Registry/Block #1,368,195

Block #1,368,195

1CCLength 10β˜…β˜…β˜†β˜†β˜†

Cunningham Chain of the First Kind Β· Discovered 12/13/2015, 5:22:17 PM Β· Difficulty 10.8372 Β· 5,458,887 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
7c4d27d12639c362ad1eeb5b4f3aa0d9ccb0ebdb45689c64aa2df162bec8c22c
View on Chainz β†—

Difficulty

10.837183

Transactions

1

Size

243 B

Version

2

Bits

0ad6519b

Nonce

1,142,793,797

Timestamp

12/13/2015, 5:22:17 PM

Confirmations

5,458,887

Merkle Root

b54cc5ed238fcaa406b3f4bbf2d609ee756115ec6c0017328cb62e62d8af81d8
Transactions (1)
Coinbaseb54cc5ed238fca…b62e62d8af81d8
1 in β†’ 2 out8.5000 XPM152 B
AXyURe5W…4RkBkCpGALPu3s2c…EJXLjVFh
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.

4.809 Γ— 10⁹⁢(97-digit number)
48098733154536655092…60110824153055124480
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
4.809 Γ— 10⁹⁢(97-digit number)
48098733154536655092…60110824153055124479
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2+1 β†’
2
2^1 Γ— origin βˆ’ 1
9.619 Γ— 10⁹⁢(97-digit number)
96197466309073310185…20221648306110248959
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2+1 β†’
3
2^2 Γ— origin βˆ’ 1
1.923 Γ— 10⁹⁷(98-digit number)
19239493261814662037…40443296612220497919
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2+1 β†’
4
2^3 Γ— origin βˆ’ 1
3.847 Γ— 10⁹⁷(98-digit number)
38478986523629324074…80886593224440995839
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2+1 β†’
5
2^4 Γ— origin βˆ’ 1
7.695 Γ— 10⁹⁷(98-digit number)
76957973047258648148…61773186448881991679
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2+1 β†’
6
2^5 Γ— origin βˆ’ 1
1.539 Γ— 10⁹⁸(99-digit number)
15391594609451729629…23546372897763983359
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2+1 β†’
7
2^6 Γ— origin βˆ’ 1
3.078 Γ— 10⁹⁸(99-digit number)
30783189218903459259…47092745795527966719
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2+1 β†’
8
2^7 Γ— origin βˆ’ 1
6.156 Γ— 10⁹⁸(99-digit number)
61566378437806918518…94185491591055933439
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2+1 β†’
9
2^8 Γ— origin βˆ’ 1
1.231 Γ— 10⁹⁹(100-digit number)
12313275687561383703…88370983182111866879
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2+1 β†’
10
2^9 Γ— origin βˆ’ 1
2.462 Γ— 10⁹⁹(100-digit number)
24626551375122767407…76741966364223733759
Verify on FactorDB β†—Wolfram Alpha β†—

What this block proved

The miner who found this block proved the existence of 10 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
UncommonChain length 10
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 1368195

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 7c4d27d12639c362ad1eeb5b4f3aa0d9ccb0ebdb45689c64aa2df162bec8c22c

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 #1,368,195 on Chainz β†—
Circulating Supply:57,860,841 XPMΒ·at block #6,827,081 Β· updates every 60s
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AQZeJoQ81VgeHQBpEYTgvNqV1gnz3L5SvK

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