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Home/Chain Registry/Block #1,534,566

Block #1,534,566

2CCLength 10β˜…β˜…β˜†β˜†β˜†

Cunningham Chain of the Second Kind Β· Discovered 4/10/2016, 8:12:49 AM Β· Difficulty 10.6168 Β· 5,306,254 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
9acfe2c3c55b938f6e790f5b62fc14d38dc8543950e53e06c5d93ec636aa7bbd
View on Chainz β†—

Difficulty

10.616802

Transactions

2

Size

7.61 KB

Version

2

Bits

0a9de6bb

Nonce

1,400,100,464

Timestamp

4/10/2016, 8:12:49 AM

Confirmations

5,306,254

Merkle Root

9a9fe7541d0f46caac6862084b933613b8208fc873ac44ffe742873832f48396
Transactions (2)
Coinbase4960ed0d01b722…a5cff2e2049fc5
1 in β†’ 1 out8.9400 XPM109 B
ATHam3Hi…ZAE5s9DH
ffbe2500ae5e37…203315bc591d92
51 in β†’ 1 out2871.3339 XPM7.42 KB
AR5BvxZd…Y6xdhVo2
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.

7.994 Γ— 10⁹³(94-digit number)
79946081995405730508…04632186545428920160
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
7.994 Γ— 10⁹³(94-digit number)
79946081995405730508…04632186545428920161
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
2
2^1 Γ— origin + 1
1.598 Γ— 10⁹⁴(95-digit number)
15989216399081146101…09264373090857840321
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
3
2^2 Γ— origin + 1
3.197 Γ— 10⁹⁴(95-digit number)
31978432798162292203…18528746181715680641
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
4
2^3 Γ— origin + 1
6.395 Γ— 10⁹⁴(95-digit number)
63956865596324584406…37057492363431361281
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
5
2^4 Γ— origin + 1
1.279 Γ— 10⁹⁡(96-digit number)
12791373119264916881…74114984726862722561
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
6
2^5 Γ— origin + 1
2.558 Γ— 10⁹⁡(96-digit number)
25582746238529833762…48229969453725445121
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
7
2^6 Γ— origin + 1
5.116 Γ— 10⁹⁡(96-digit number)
51165492477059667525…96459938907450890241
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
8
2^7 Γ— origin + 1
1.023 Γ— 10⁹⁢(97-digit number)
10233098495411933505…92919877814901780481
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
9
2^8 Γ— origin + 1
2.046 Γ— 10⁹⁢(97-digit number)
20466196990823867010…85839755629803560961
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
10
2^9 Γ— origin + 1
4.093 Γ— 10⁹⁢(97-digit number)
40932393981647734020…71679511259607121921
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 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
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 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 1534566

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 9acfe2c3c55b938f6e790f5b62fc14d38dc8543950e53e06c5d93ec636aa7bbd

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 #1,534,566 on Chainz β†—
Circulating Supply:57,970,912 XPMΒ·at block #6,840,819 Β· updates every 60s
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