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Home/Chain Registry/Block #1,420,036

Block #1,420,036

1CCLength 10β˜…β˜…β˜†β˜†β˜†

Cunningham Chain of the First Kind Β· Discovered 1/19/2016, 3:37:05 PM Β· Difficulty 10.7897 Β· 5,420,417 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
d524373e6830c16e4ba94788dba86b4226f5c3234f138c41bbebcd6b79c70205
View on Chainz β†—

Difficulty

10.789696

Transactions

1

Size

200 B

Version

2

Bits

0aca2980

Nonce

1,501,606,713

Timestamp

1/19/2016, 3:37:05 PM

Confirmations

5,420,417

Merkle Root

1d7027b4876f3736ea821a83c5e73b6f2d7435eaececc0980eeeac68d2e54413
Transactions (1)
Coinbase1d7027b4876f37…eeac68d2e54413
1 in β†’ 1 out8.5800 XPM110 B
AZEq673f…QHc63v7o
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.

9.340 Γ— 10⁹⁴(95-digit number)
93403343864274229451…69274702622932757760
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
9.340 Γ— 10⁹⁴(95-digit number)
93403343864274229451…69274702622932757759
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2+1 β†’
2
2^1 Γ— origin βˆ’ 1
1.868 Γ— 10⁹⁡(96-digit number)
18680668772854845890…38549405245865515519
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2+1 β†’
3
2^2 Γ— origin βˆ’ 1
3.736 Γ— 10⁹⁡(96-digit number)
37361337545709691780…77098810491731031039
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2+1 β†’
4
2^3 Γ— origin βˆ’ 1
7.472 Γ— 10⁹⁡(96-digit number)
74722675091419383561…54197620983462062079
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2+1 β†’
5
2^4 Γ— origin βˆ’ 1
1.494 Γ— 10⁹⁢(97-digit number)
14944535018283876712…08395241966924124159
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2+1 β†’
6
2^5 Γ— origin βˆ’ 1
2.988 Γ— 10⁹⁢(97-digit number)
29889070036567753424…16790483933848248319
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2+1 β†’
7
2^6 Γ— origin βˆ’ 1
5.977 Γ— 10⁹⁢(97-digit number)
59778140073135506848…33580967867696496639
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2+1 β†’
8
2^7 Γ— origin βˆ’ 1
1.195 Γ— 10⁹⁷(98-digit number)
11955628014627101369…67161935735392993279
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2+1 β†’
9
2^8 Γ— origin βˆ’ 1
2.391 Γ— 10⁹⁷(98-digit number)
23911256029254202739…34323871470785986559
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2+1 β†’
10
2^9 Γ— origin βˆ’ 1
4.782 Γ— 10⁹⁷(98-digit number)
47822512058508405479…68647742941571973119
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 1420036

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 d524373e6830c16e4ba94788dba86b4226f5c3234f138c41bbebcd6b79c70205

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 #1,420,036 on Chainz β†—
Circulating Supply:57,967,955 XPMΒ·at block #6,840,452 Β· updates every 60s
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