Home/Chain Registry/Block #149,104

Block #149,104

2CCLength 9★☆☆☆☆

Cunningham Chain of the Second Kind · Discovered 9/4/2013, 3:56:47 AM · Difficulty 9.8567 · 6,642,319 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
fe22b5a969090e40dea5621a88688e2802f1c11ae2d26b4dd5d8a65b465f1421

Height

#149,104

Difficulty

9.856668

Transactions

7

Size

1.51 KB

Version

2

Bits

09db4e9a

Nonce

411,786

Timestamp

9/4/2013, 3:56:47 AM

Confirmations

6,642,319

Merkle Root

ee9e4a26d238b3a3365549c38a1471268b43dabcc68299f88ff13c4b9c393804
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.

4.863 × 10⁹⁰(91-digit number)
48632158030928251807…47407945470445617040
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
4.863 × 10⁹⁰(91-digit number)
48632158030928251807…47407945470445617041
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
9.726 × 10⁹⁰(91-digit number)
97264316061856503614…94815890940891234081
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
1.945 × 10⁹¹(92-digit number)
19452863212371300722…89631781881782468161
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
3.890 × 10⁹¹(92-digit number)
38905726424742601445…79263563763564936321
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
7.781 × 10⁹¹(92-digit number)
77811452849485202891…58527127527129872641
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
1.556 × 10⁹²(93-digit number)
15562290569897040578…17054255054259745281
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
3.112 × 10⁹²(93-digit number)
31124581139794081156…34108510108519490561
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
6.224 × 10⁹²(93-digit number)
62249162279588162313…68217020217038981121
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
1.244 × 10⁹³(94-digit number)
12449832455917632462…36434040434077962241
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 149104

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 fe22b5a969090e40dea5621a88688e2802f1c11ae2d26b4dd5d8a65b465f1421

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 #149,104 on Chainz ↗
Circulating Supply:57,575,322 XPM·at block #6,791,422 · updates every 60s
xpmprime.info is a work in progress. If you enjoy using this service you can support this project with a Primecoin donation.