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Home/Chain Registry/Block #191,613

Block #191,613

1CCLength 9★☆☆☆☆

Cunningham Chain of the First Kind · Discovered 10/3/2013, 6:52:38 AM · Difficulty 9.8752 · 6,599,610 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
ed2e5f96ca9bac6d6f4fac7575a79803c3121206f6ae149885f960a420a8d84a

Height

#191,613

Difficulty

9.875190

Transactions

6

Size

1.83 KB

Version

2

Bits

09e00c78

Nonce

20,651

Timestamp

10/3/2013, 6:52:38 AM

Confirmations

6,599,610

Merkle Root

8333242aabb0c0aa102a04f9fd5bcdc8b51ab2f638bef9847d64105afa315e5e
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.

3.266 × 10⁹⁸(99-digit number)
32661137195128682446…16473792346939791360
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
3.266 × 10⁹⁸(99-digit number)
32661137195128682446…16473792346939791359
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
6.532 × 10⁹⁸(99-digit number)
65322274390257364892…32947584693879582719
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
1.306 × 10⁹⁹(100-digit number)
13064454878051472978…65895169387759165439
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
2.612 × 10⁹⁹(100-digit number)
26128909756102945957…31790338775518330879
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
5.225 × 10⁹⁹(100-digit number)
52257819512205891914…63580677551036661759
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
1.045 × 10¹⁰⁰(101-digit number)
10451563902441178382…27161355102073323519
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
2.090 × 10¹⁰⁰(101-digit number)
20903127804882356765…54322710204146647039
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
4.180 × 10¹⁰⁰(101-digit number)
41806255609764713531…08645420408293294079
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
8.361 × 10¹⁰⁰(101-digit number)
83612511219529427062…17290840816586588159
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 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
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 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 191613

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 ed2e5f96ca9bac6d6f4fac7575a79803c3121206f6ae149885f960a420a8d84a

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 #191,613 on Chainz ↗
Circulating Supply:57,573,717 XPM·at block #6,791,222 · updates every 60s
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