Home/Chain Registry/Block #3,005,061

Block #3,005,061

1CCLength 11★★★☆☆

Cunningham Chain of the First Kind · Discovered 1/11/2019, 2:26:31 PM · Difficulty 11.2007 · 3,834,066 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
973d2624c65d8ab9978bba110cb7d304c0b9cb93002e0389833856b795adc94a

Difficulty

11.200744

Transactions

14

Size

4.76 KB

Version

2

Bits

0b3363fa

Nonce

857,011,616

Timestamp

1/11/2019, 2:26:31 PM

Confirmations

3,834,066

Merkle Root

74ab1b5da702c4e45fcc19c6dc4f01831dc414622f55f8d4b4e8761546b01f43
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.

7.482 × 10⁹⁴(95-digit number)
74823932085228568717…24398776480892389930
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
7.482 × 10⁹⁴(95-digit number)
74823932085228568717…24398776480892389929
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
1.496 × 10⁹⁵(96-digit number)
14964786417045713743…48797552961784779859
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
2.992 × 10⁹⁵(96-digit number)
29929572834091427486…97595105923569559719
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
5.985 × 10⁹⁵(96-digit number)
59859145668182854973…95190211847139119439
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
1.197 × 10⁹⁶(97-digit number)
11971829133636570994…90380423694278238879
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
2.394 × 10⁹⁶(97-digit number)
23943658267273141989…80760847388556477759
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
4.788 × 10⁹⁶(97-digit number)
47887316534546283979…61521694777112955519
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
9.577 × 10⁹⁶(97-digit number)
95774633069092567958…23043389554225911039
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
1.915 × 10⁹⁷(98-digit number)
19154926613818513591…46086779108451822079
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
3.830 × 10⁹⁷(98-digit number)
38309853227637027183…92173558216903644159
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
11
2^10 × origin − 1
7.661 × 10⁹⁷(98-digit number)
76619706455274054366…84347116433807288319
Verify on FactorDB ↗Wolfram Alpha ↗

What this block proved

The miner who found this block proved the existence of 11 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
RareChain length 11
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 3005061

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 973d2624c65d8ab9978bba110cb7d304c0b9cb93002e0389833856b795adc94a

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 #3,005,061 on Chainz ↗
Circulating Supply:57,957,292 XPM·at block #6,839,126 · updates every 60s
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