Home/Chain Registry/Block #316,863

Block #316,863

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 12/17/2013, 7:58:09 AM · Difficulty 10.1457 · 6,499,702 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
fbcf64b33cf50beaa6579a3b36f42c1e6be84ce8c504a0e4e11d9f1f29d4213f

Height

#316,863

Difficulty

10.145696

Transactions

27

Size

8.34 KB

Version

2

Bits

0a254c53

Nonce

81,675

Timestamp

12/17/2013, 7:58:09 AM

Confirmations

6,499,702

Merkle Root

0f92c1869824a13f5168b2f0a677ad3f583bd36bac40d656894aae53353d6be5
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.

1.467 × 10⁹⁸(99-digit number)
14674002377622210949…36846428578773762240
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
1.467 × 10⁹⁸(99-digit number)
14674002377622210949…36846428578773762239
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
2.934 × 10⁹⁸(99-digit number)
29348004755244421898…73692857157547524479
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
5.869 × 10⁹⁸(99-digit number)
58696009510488843796…47385714315095048959
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
1.173 × 10⁹⁹(100-digit number)
11739201902097768759…94771428630190097919
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
2.347 × 10⁹⁹(100-digit number)
23478403804195537518…89542857260380195839
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
4.695 × 10⁹⁹(100-digit number)
46956807608391075037…79085714520760391679
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
9.391 × 10⁹⁹(100-digit number)
93913615216782150074…58171429041520783359
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
1.878 × 10¹⁰⁰(101-digit number)
18782723043356430014…16342858083041566719
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
3.756 × 10¹⁰⁰(101-digit number)
37565446086712860029…32685716166083133439
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
7.513 × 10¹⁰⁰(101-digit number)
75130892173425720059…65371432332166266879
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 316863

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 fbcf64b33cf50beaa6579a3b36f42c1e6be84ce8c504a0e4e11d9f1f29d4213f

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 #316,863 on Chainz ↗
Circulating Supply:57,776,651 XPM·at block #6,816,564 · updates every 60s
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