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Home/Chain Registry/Block #926,276

Block #926,276

1CCLength 10β˜…β˜…β˜†β˜†β˜†

Cunningham Chain of the First Kind Β· Discovered 2/7/2015, 10:47:30 AM Β· Difficulty 10.9080 Β· 5,879,029 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
80108fdc79ca2ff54f4e377abd67215f0249cb08bc1db2dae03467330da12ee3
View on Chainz β†—

Height

#926,276

Difficulty

10.907994

Transactions

1

Size

206 B

Version

2

Bits

0ae87244

Nonce

275,336,229

Timestamp

2/7/2015, 10:47:30 AM

Confirmations

5,879,029

Merkle Root

9207ac0d5e231c20b1cecdb7a6ca7729b71ca8a527b77b5b5fc2307fab74c7fb
Transactions (1)
Coinbase9207ac0d5e231c…c2307fab74c7fb
1 in β†’ 1 out8.3900 XPM116 B
ANSXnLY2…Sd25TjkD
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.

2.000 Γ— 10⁹⁡(96-digit number)
20000545131628234132…37094789290961284800
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
2.000 Γ— 10⁹⁡(96-digit number)
20000545131628234132…37094789290961284799
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2+1 β†’
2
2^1 Γ— origin βˆ’ 1
4.000 Γ— 10⁹⁡(96-digit number)
40001090263256468265…74189578581922569599
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2+1 β†’
3
2^2 Γ— origin βˆ’ 1
8.000 Γ— 10⁹⁡(96-digit number)
80002180526512936530…48379157163845139199
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2+1 β†’
4
2^3 Γ— origin βˆ’ 1
1.600 Γ— 10⁹⁢(97-digit number)
16000436105302587306…96758314327690278399
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2+1 β†’
5
2^4 Γ— origin βˆ’ 1
3.200 Γ— 10⁹⁢(97-digit number)
32000872210605174612…93516628655380556799
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2+1 β†’
6
2^5 Γ— origin βˆ’ 1
6.400 Γ— 10⁹⁢(97-digit number)
64001744421210349224…87033257310761113599
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2+1 β†’
7
2^6 Γ— origin βˆ’ 1
1.280 Γ— 10⁹⁷(98-digit number)
12800348884242069844…74066514621522227199
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2+1 β†’
8
2^7 Γ— origin βˆ’ 1
2.560 Γ— 10⁹⁷(98-digit number)
25600697768484139689…48133029243044454399
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2+1 β†’
9
2^8 Γ— origin βˆ’ 1
5.120 Γ— 10⁹⁷(98-digit number)
51201395536968279379…96266058486088908799
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2+1 β†’
10
2^9 Γ— origin βˆ’ 1
1.024 Γ— 10⁹⁸(99-digit number)
10240279107393655875…92532116972177817599
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 926276

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 80108fdc79ca2ff54f4e377abd67215f0249cb08bc1db2dae03467330da12ee3

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 #926,276 on Chainz β†—
Circulating Supply:57,686,516 XPMΒ·at block #6,805,304 Β· updates every 60s
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