Home/Chain Registry/Block #301,457

Block #301,457

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 12/9/2013, 5:07:29 AM · Difficulty 9.9925 · 6,511,414 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
16862e5ce9689f0eb774a30521e911cdb26a7aa3bca31bc977aebb2eced21ccf

Height

#301,457

Difficulty

9.992532

Transactions

8

Size

4.78 KB

Version

2

Bits

09fe1696

Nonce

72,197

Timestamp

12/9/2013, 5:07:29 AM

Confirmations

6,511,414

Merkle Root

9fcd69a8763aba94fac90fc5edf08185bb36004b64cecb89792720091b22e8e7
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.

3.001 × 10⁹³(94-digit number)
30014835125983492202…23794688343275407180
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
3.001 × 10⁹³(94-digit number)
30014835125983492202…23794688343275407179
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
6.002 × 10⁹³(94-digit number)
60029670251966984405…47589376686550814359
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
1.200 × 10⁹⁴(95-digit number)
12005934050393396881…95178753373101628719
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
2.401 × 10⁹⁴(95-digit number)
24011868100786793762…90357506746203257439
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
4.802 × 10⁹⁴(95-digit number)
48023736201573587524…80715013492406514879
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
9.604 × 10⁹⁴(95-digit number)
96047472403147175048…61430026984813029759
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
1.920 × 10⁹⁵(96-digit number)
19209494480629435009…22860053969626059519
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
3.841 × 10⁹⁵(96-digit number)
38418988961258870019…45720107939252119039
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
7.683 × 10⁹⁵(96-digit number)
76837977922517740038…91440215878504238079
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
1.536 × 10⁹⁶(97-digit number)
15367595584503548007…82880431757008476159
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 301457

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 16862e5ce9689f0eb774a30521e911cdb26a7aa3bca31bc977aebb2eced21ccf

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 #301,457 on Chainz ↗
Circulating Supply:57,746,998 XPM·at block #6,812,870 · updates every 60s
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