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Home/Chain Registry/Block #1,476,158

Block #1,476,158

2CCLength 10β˜…β˜…β˜†β˜†β˜†

Cunningham Chain of the Second Kind Β· Discovered 2/28/2016, 10:08:25 PM Β· Difficulty 10.6978 Β· 5,368,944 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
fb7db4e48eca71b77569883fb54e65c1adba5d385553aca730c1dac22817c9e2
View on Chainz β†—

Difficulty

10.697787

Transactions

1

Size

199 B

Version

2

Bits

0ab2a232

Nonce

179,388,345

Timestamp

2/28/2016, 10:08:25 PM

Confirmations

5,368,944

Merkle Root

927fa844c4810024516a058c7d85c8f593eaf130a4e32a48283f8d4b8c3c4c6e
Transactions (1)
Coinbase927fa844c48100…3f8d4b8c3c4c6e
1 in β†’ 1 out8.7200 XPM109 B
AYLgB7tZ…ww2M58nR
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.

6.080 Γ— 10⁹⁴(95-digit number)
60808700988941254840…64886416417017166320
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
6.080 Γ— 10⁹⁴(95-digit number)
60808700988941254840…64886416417017166321
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
2
2^1 Γ— origin + 1
1.216 Γ— 10⁹⁡(96-digit number)
12161740197788250968…29772832834034332641
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
3
2^2 Γ— origin + 1
2.432 Γ— 10⁹⁡(96-digit number)
24323480395576501936…59545665668068665281
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
4
2^3 Γ— origin + 1
4.864 Γ— 10⁹⁡(96-digit number)
48646960791153003872…19091331336137330561
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
5
2^4 Γ— origin + 1
9.729 Γ— 10⁹⁡(96-digit number)
97293921582306007744…38182662672274661121
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
6
2^5 Γ— origin + 1
1.945 Γ— 10⁹⁢(97-digit number)
19458784316461201548…76365325344549322241
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
7
2^6 Γ— origin + 1
3.891 Γ— 10⁹⁢(97-digit number)
38917568632922403097…52730650689098644481
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
8
2^7 Γ— origin + 1
7.783 Γ— 10⁹⁢(97-digit number)
77835137265844806195…05461301378197288961
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
9
2^8 Γ— origin + 1
1.556 Γ— 10⁹⁷(98-digit number)
15567027453168961239…10922602756394577921
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
10
2^9 Γ— origin + 1
3.113 Γ— 10⁹⁷(98-digit number)
31134054906337922478…21845205512789155841
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 1476158

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 fb7db4e48eca71b77569883fb54e65c1adba5d385553aca730c1dac22817c9e2

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 #1,476,158 on Chainz β†—
Circulating Supply:58,005,243 XPMΒ·at block #6,845,101 Β· updates every 60s
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AQZeJoQ81VgeHQBpEYTgvNqV1gnz3L5SvK

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