Home/Chain Registry/Block #1,424,259

Block #1,424,259

2CCLength 10β˜…β˜…β˜†β˜†β˜†

Cunningham Chain of the Second Kind Β· Discovered 1/22/2016, 8:02:59 PM Β· Difficulty 10.7741 Β· 5,415,486 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
4ef10a42775e94a8469c3b1af92c50c9dda7fed2d0f6d44bd76fe9492135d503

Difficulty

10.774069

Transactions

1

Size

200 B

Version

2

Bits

0ac6295d

Nonce

1,146,023,005

Timestamp

1/22/2016, 8:02:59 PM

Confirmations

5,415,486

Merkle Root

041f9c1696550012d0f4154452aaea9752ba51d1d5e849118b0995a2e56943c4
Transactions (1)
1 in β†’ 1 out8.6000 XPM110 B
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.

2.625 Γ— 10⁹⁡(96-digit number)
26254691777892029384…75157970226926121600
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
2.625 Γ— 10⁹⁡(96-digit number)
26254691777892029384…75157970226926121601
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
2
2^1 Γ— origin + 1
5.250 Γ— 10⁹⁡(96-digit number)
52509383555784058769…50315940453852243201
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
3
2^2 Γ— origin + 1
1.050 Γ— 10⁹⁢(97-digit number)
10501876711156811753…00631880907704486401
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
4
2^3 Γ— origin + 1
2.100 Γ— 10⁹⁢(97-digit number)
21003753422313623507…01263761815408972801
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
5
2^4 Γ— origin + 1
4.200 Γ— 10⁹⁢(97-digit number)
42007506844627247015…02527523630817945601
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
6
2^5 Γ— origin + 1
8.401 Γ— 10⁹⁢(97-digit number)
84015013689254494030…05055047261635891201
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
7
2^6 Γ— origin + 1
1.680 Γ— 10⁹⁷(98-digit number)
16803002737850898806…10110094523271782401
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
8
2^7 Γ— origin + 1
3.360 Γ— 10⁹⁷(98-digit number)
33606005475701797612…20220189046543564801
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
9
2^8 Γ— origin + 1
6.721 Γ— 10⁹⁷(98-digit number)
67212010951403595224…40440378093087129601
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
10
2^9 Γ— origin + 1
1.344 Γ— 10⁹⁸(99-digit number)
13442402190280719044…80880756186174259201
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 1424259

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 4ef10a42775e94a8469c3b1af92c50c9dda7fed2d0f6d44bd76fe9492135d503

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 #1,424,259 on Chainz β†—
Circulating Supply:57,962,247 XPMΒ·at block #6,839,744 Β· updates every 60s
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