Home/Chain Registry/Block #478,987

Block #478,987

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 4/7/2014, 10:27:26 AM · Difficulty 10.4987 · 6,324,574 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
dbe835cb5cb3e59cd3a25b9ba0c8df19621f63bcb243e529b060bdac0bd279fe

Height

#478,987

Difficulty

10.498674

Transactions

9

Size

2.10 KB

Version

2

Bits

0a7fa915

Nonce

76,659

Timestamp

4/7/2014, 10:27:26 AM

Confirmations

6,324,574

Merkle Root

8c66000fac4aeca629a1bafb637d6cdf424a0acad96975f65c6cece8f4290144
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.

9.606 × 10⁹⁷(98-digit number)
96066394744580421026…53167532428826214400
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
9.606 × 10⁹⁷(98-digit number)
96066394744580421026…53167532428826214399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
1.921 × 10⁹⁸(99-digit number)
19213278948916084205…06335064857652428799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
3.842 × 10⁹⁸(99-digit number)
38426557897832168410…12670129715304857599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
7.685 × 10⁹⁸(99-digit number)
76853115795664336820…25340259430609715199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
1.537 × 10⁹⁹(100-digit number)
15370623159132867364…50680518861219430399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
3.074 × 10⁹⁹(100-digit number)
30741246318265734728…01361037722438860799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
6.148 × 10⁹⁹(100-digit number)
61482492636531469456…02722075444877721599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
1.229 × 10¹⁰⁰(101-digit number)
12296498527306293891…05444150889755443199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
2.459 × 10¹⁰⁰(101-digit number)
24592997054612587782…10888301779510886399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
4.918 × 10¹⁰⁰(101-digit number)
49185994109225175565…21776603559021772799
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 478987

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 dbe835cb5cb3e59cd3a25b9ba0c8df19621f63bcb243e529b060bdac0bd279fe

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 #478,987 on Chainz ↗
Circulating Supply:57,672,520 XPM·at block #6,803,560 · updates every 60s
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