Home/Chain Registry/Block #270,155

Block #270,155

2CCLength 9★☆☆☆☆

Cunningham Chain of the Second Kind · Discovered 11/23/2013, 6:05:27 PM · Difficulty 9.9518 · 6,522,765 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
0bf24a135a24810e5b3c71faa47e582493a51a7247d2427c3058c1ddae32fdb7

Height

#270,155

Difficulty

9.951770

Transactions

5

Size

2.12 KB

Version

2

Bits

09f3a72d

Nonce

104,722

Timestamp

11/23/2013, 6:05:27 PM

Confirmations

6,522,765

Merkle Root

fb0aa8f3320b1aef92d0eb118ea705b50e3b1edd5d0d7c757d6f9f273bff3806
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.

3.373 × 10⁹⁷(98-digit number)
33735932950590523453…00323125760841226240
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
3.373 × 10⁹⁷(98-digit number)
33735932950590523453…00323125760841226241
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
6.747 × 10⁹⁷(98-digit number)
67471865901181046906…00646251521682452481
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
1.349 × 10⁹⁸(99-digit number)
13494373180236209381…01292503043364904961
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
2.698 × 10⁹⁸(99-digit number)
26988746360472418762…02585006086729809921
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
5.397 × 10⁹⁸(99-digit number)
53977492720944837524…05170012173459619841
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
1.079 × 10⁹⁹(100-digit number)
10795498544188967504…10340024346919239681
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
2.159 × 10⁹⁹(100-digit number)
21590997088377935009…20680048693838479361
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
4.318 × 10⁹⁹(100-digit number)
43181994176755870019…41360097387676958721
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
8.636 × 10⁹⁹(100-digit number)
86363988353511740039…82720194775353917441
Verify on FactorDB ↗Wolfram Alpha ↗

What this block proved

The miner who found this block proved the existence of 9 consecutive prime numbers forming a Cunningham Chain of the Second 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
CommonChain length 9
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 2CC formula:

2CC: 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 270155

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 0bf24a135a24810e5b3c71faa47e582493a51a7247d2427c3058c1ddae32fdb7

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 #270,155 on Chainz ↗
Circulating Supply:57,587,340 XPM·at block #6,792,919 · updates every 60s
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