Home/Chain Registry/Block #2,271,143

Block #2,271,143

2CCLength 10β˜…β˜…β˜†β˜†β˜†

Cunningham Chain of the Second Kind Β· Discovered 8/28/2017, 1:38:10 AM Β· Difficulty 10.9534 Β· 4,570,765 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
3003a21d656b49ea8faaf36c67e812226f23f00c006cc7cb3b2e100656c1a5f0

Difficulty

10.953441

Transactions

1

Size

201 B

Version

2

Bits

0af414b8

Nonce

1,630,037,877

Timestamp

8/28/2017, 1:38:10 AM

Confirmations

4,570,765

Merkle Root

269ebc1fa79871f344ae3186a145a57d54e3088eebab81f3d8ec68d06bd8372f
Transactions (1)
1 in β†’ 1 out8.3200 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.

2.796 Γ— 10⁹⁢(97-digit number)
27962263660877767115…69309519430175887360
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
2.796 Γ— 10⁹⁢(97-digit number)
27962263660877767115…69309519430175887361
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
2
2^1 Γ— origin + 1
5.592 Γ— 10⁹⁢(97-digit number)
55924527321755534230…38619038860351774721
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
3
2^2 Γ— origin + 1
1.118 Γ— 10⁹⁷(98-digit number)
11184905464351106846…77238077720703549441
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
4
2^3 Γ— origin + 1
2.236 Γ— 10⁹⁷(98-digit number)
22369810928702213692…54476155441407098881
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
5
2^4 Γ— origin + 1
4.473 Γ— 10⁹⁷(98-digit number)
44739621857404427384…08952310882814197761
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
6
2^5 Γ— origin + 1
8.947 Γ— 10⁹⁷(98-digit number)
89479243714808854768…17904621765628395521
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
7
2^6 Γ— origin + 1
1.789 Γ— 10⁹⁸(99-digit number)
17895848742961770953…35809243531256791041
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
8
2^7 Γ— origin + 1
3.579 Γ— 10⁹⁸(99-digit number)
35791697485923541907…71618487062513582081
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
9
2^8 Γ— origin + 1
7.158 Γ— 10⁹⁸(99-digit number)
71583394971847083814…43236974125027164161
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
10
2^9 Γ— origin + 1
1.431 Γ— 10⁹⁹(100-digit number)
14316678994369416762…86473948250054328321
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 2271143

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 3003a21d656b49ea8faaf36c67e812226f23f00c006cc7cb3b2e100656c1a5f0

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 #2,271,143 on Chainz β†—
Circulating Supply:57,979,639 XPMΒ·at block #6,841,907 Β· updates every 60s
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