Home/Chain Registry/Block #790,871

Block #790,871

1CCLength 11★★★☆☆

Cunningham Chain of the First Kind · Discovered 10/31/2014, 3:31:09 PM · Difficulty 10.9733 · 6,021,296 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
c20a95c7b60b746884a6011bc16d721632270404a9cf806eb1bcf29759d05627

Height

#790,871

Difficulty

10.973287

Transactions

5

Size

2.06 KB

Version

2

Bits

0af92954

Nonce

956,942,239

Timestamp

10/31/2014, 3:31:09 PM

Confirmations

6,021,296

Merkle Root

1d3799ecf026fc22ff3102d7da5c27d76d9d5cb40bb3f35515ab431053c69b7f
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.

2.664 × 10⁹⁶(97-digit number)
26647036169148352027…04688013474085259160
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
2.664 × 10⁹⁶(97-digit number)
26647036169148352027…04688013474085259159
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
5.329 × 10⁹⁶(97-digit number)
53294072338296704054…09376026948170518319
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
1.065 × 10⁹⁷(98-digit number)
10658814467659340810…18752053896341036639
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
2.131 × 10⁹⁷(98-digit number)
21317628935318681621…37504107792682073279
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
4.263 × 10⁹⁷(98-digit number)
42635257870637363243…75008215585364146559
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
8.527 × 10⁹⁷(98-digit number)
85270515741274726486…50016431170728293119
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
1.705 × 10⁹⁸(99-digit number)
17054103148254945297…00032862341456586239
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
3.410 × 10⁹⁸(99-digit number)
34108206296509890594…00065724682913172479
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
6.821 × 10⁹⁸(99-digit number)
68216412593019781189…00131449365826344959
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
1.364 × 10⁹⁹(100-digit number)
13643282518603956237…00262898731652689919
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
11
2^10 × origin − 1
2.728 × 10⁹⁹(100-digit number)
27286565037207912475…00525797463305379839
Verify on FactorDB ↗Wolfram Alpha ↗

What this block proved

The miner who found this block proved the existence of 11 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
RareChain length 11
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 790871

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 c20a95c7b60b746884a6011bc16d721632270404a9cf806eb1bcf29759d05627

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 #790,871 on Chainz ↗
Circulating Supply:57,741,355 XPM·at block #6,812,166 · updates every 60s
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