Home/Chain Registry/Block #290,660

Block #290,660

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 12/2/2013, 7:25:12 PM · Difficulty 9.9894 · 6,535,874 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
a0aed21fcf33d266df44d9544691df03d08372b70fea75547709739b66a16025

Height

#290,660

Difficulty

9.989364

Transactions

7

Size

1.80 KB

Version

2

Bits

09fd46fc

Nonce

1,767

Timestamp

12/2/2013, 7:25:12 PM

Confirmations

6,535,874

Merkle Root

3dcad026948d25dd260951f66ecf34e215704a1abde611b5457a3954d0850743
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.

9.547 × 10¹⁰³(104-digit number)
95477152616566040722…52813063469987567040
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
9.547 × 10¹⁰³(104-digit number)
95477152616566040722…52813063469987567039
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
1.909 × 10¹⁰⁴(105-digit number)
19095430523313208144…05626126939975134079
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
3.819 × 10¹⁰⁴(105-digit number)
38190861046626416288…11252253879950268159
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
7.638 × 10¹⁰⁴(105-digit number)
76381722093252832577…22504507759900536319
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
1.527 × 10¹⁰⁵(106-digit number)
15276344418650566515…45009015519801072639
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
3.055 × 10¹⁰⁵(106-digit number)
30552688837301133031…90018031039602145279
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
6.110 × 10¹⁰⁵(106-digit number)
61105377674602266062…80036062079204290559
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
1.222 × 10¹⁰⁶(107-digit number)
12221075534920453212…60072124158408581119
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
2.444 × 10¹⁰⁶(107-digit number)
24442151069840906424…20144248316817162239
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
4.888 × 10¹⁰⁶(107-digit number)
48884302139681812849…40288496633634324479
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 290660

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 a0aed21fcf33d266df44d9544691df03d08372b70fea75547709739b66a16025

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 #290,660 on Chainz ↗
Circulating Supply:57,856,419 XPM·at block #6,826,533 · updates every 60s
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