Home/Chain Registry/Block #270,670

Block #270,670

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 11/24/2013, 2:57:13 AM · Difficulty 9.9516 · 6,521,194 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
43d81818b30597de0397ceeb9bb392c5b37991310a8c060f32d0dc821e647a94

Height

#270,670

Difficulty

9.951635

Transactions

6

Size

3.03 KB

Version

2

Bits

09f39e5a

Nonce

89,963

Timestamp

11/24/2013, 2:57:13 AM

Confirmations

6,521,194

Merkle Root

03ce46676650ed8e08163377c2c4163ddd44a8f27d6203d99c947742e7f1b674
Prime Chain Origin

This is the prime chain origin stored in the block header. It is a composite number (not prime itself) — it equals the first prime in the chain multiplied by a primorial. The origin anchors the entire chain to this specific block.

4.925 × 10⁹⁴(95-digit number)
49254294006879587866…25155121860718337600
Discovered Prime Numbers
p_k = 2^k × 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
4.925 × 10⁹⁴(95-digit number)
49254294006879587866…25155121860718337599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
9.850 × 10⁹⁴(95-digit number)
98508588013759175733…50310243721436675199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
1.970 × 10⁹⁵(96-digit number)
19701717602751835146…00620487442873350399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
3.940 × 10⁹⁵(96-digit number)
39403435205503670293…01240974885746700799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
7.880 × 10⁹⁵(96-digit number)
78806870411007340586…02481949771493401599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
1.576 × 10⁹⁶(97-digit number)
15761374082201468117…04963899542986803199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
3.152 × 10⁹⁶(97-digit number)
31522748164402936234…09927799085973606399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
6.304 × 10⁹⁶(97-digit number)
63045496328805872469…19855598171947212799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
1.260 × 10⁹⁷(98-digit number)
12609099265761174493…39711196343894425599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
2.521 × 10⁹⁷(98-digit number)
25218198531522348987…79422392687788851199
Verify on FactorDB ↗Wolfram Alpha ↗

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 — the large number shown above — 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 →
★★☆☆☆
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 × 3 × 5 × 7 × …), the result is the first prime in the chain. The origin is deliberately divisible by this primorial — that divisibility is part of the proof.

Prime Chain Origin = First Prime × Primorial (2·3·5·7·11·…)
Source: Primecoin prime.cpp — CheckPrimeProofOfWork()

This is why the origin has many small prime factors — those factors are the primorial divisor. The chain then extends from the first prime using the 1CC formula:

1CC: p₁ (first prime), p₂ = 2p₁ + 1, p₃ = 2p₂ + 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 270670

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 43d81818b30597de0397ceeb9bb392c5b37991310a8c060f32d0dc821e647a94

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 → Debug Window → 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 #270,670 on Chainz ↗
Circulating Supply:57,578,867 XPM·at block #6,791,863 · updates every 60s
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