Home/Chain Registry/Block #526,960

Block #526,960

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 5/5/2014, 5:25:38 PM · Difficulty 10.8837 · 6,299,730 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
f012a91823e6830d5070b3a339fa229e31cba745467dd56f77122a5113d14ed7

Height

#526,960

Difficulty

10.883700

Transactions

6

Size

1.59 KB

Version

2

Bits

0ae23a22

Nonce

5,419,636

Timestamp

5/5/2014, 5:25:38 PM

Confirmations

6,299,730

Merkle Root

114bc723c0c8ed2f58dc73c0d2382264ce7e5253718034b01042f1a1272045be
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.

1.282 × 10¹⁰⁰(101-digit number)
12825677424266169539…46338234821377280640
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
1.282 × 10¹⁰⁰(101-digit number)
12825677424266169539…46338234821377280641
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
2.565 × 10¹⁰⁰(101-digit number)
25651354848532339078…92676469642754561281
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
5.130 × 10¹⁰⁰(101-digit number)
51302709697064678156…85352939285509122561
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
1.026 × 10¹⁰¹(102-digit number)
10260541939412935631…70705878571018245121
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
2.052 × 10¹⁰¹(102-digit number)
20521083878825871262…41411757142036490241
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
4.104 × 10¹⁰¹(102-digit number)
41042167757651742524…82823514284072980481
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
8.208 × 10¹⁰¹(102-digit number)
82084335515303485049…65647028568145960961
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
1.641 × 10¹⁰²(103-digit number)
16416867103060697009…31294057136291921921
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
3.283 × 10¹⁰²(103-digit number)
32833734206121394019…62588114272583843841
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
6.566 × 10¹⁰²(103-digit number)
65667468412242788039…25176228545167687681
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 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
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 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 526960

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 f012a91823e6830d5070b3a339fa229e31cba745467dd56f77122a5113d14ed7

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 #526,960 on Chainz ↗
Circulating Supply:57,857,671 XPM·at block #6,826,689 · updates every 60s
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