Home/Chain Registry/Block #223,900

Block #223,900

1CCLength 10β˜…β˜…β˜†β˜†β˜†

Cunningham Chain of the First Kind Β· Discovered 10/23/2013, 9:11:52 AM Β· Difficulty 9.9374 Β· 6,603,433 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
c3a217a0c24770ef86d90d0d792ef5bd4d2241c692791121acb9aada23d97bfc

Height

#223,900

Difficulty

9.937409

Transactions

1

Size

205 B

Version

2

Bits

09effa0a

Nonce

1,541

Timestamp

10/23/2013, 9:11:52 AM

Confirmations

6,603,433

Merkle Root

e2763e271770b4cbc5f1c5cd92f6584ef8901785787bdd0c8c834f4b0c03be62
Transactions (1)
1 in β†’ 1 out10.1100 XPM116 B
Prime Chain Origin

This is the prime chain origin stored in the block header. It is a composite number (not prime itself) β€” it equals the first prime in the chain multiplied by a primorial. The origin anchors the entire chain to this specific block.

6.731 Γ— 10⁹²(93-digit number)
67314974883861873284…64529048774037935240
Discovered Prime Numbers
p_k = 2^k Γ— origin βˆ’ 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 βˆ’ 1
6.731 Γ— 10⁹²(93-digit number)
67314974883861873284…64529048774037935239
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2+1 β†’
2
2^1 Γ— origin βˆ’ 1
1.346 Γ— 10⁹³(94-digit number)
13462994976772374656…29058097548075870479
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2+1 β†’
3
2^2 Γ— origin βˆ’ 1
2.692 Γ— 10⁹³(94-digit number)
26925989953544749313…58116195096151740959
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2+1 β†’
4
2^3 Γ— origin βˆ’ 1
5.385 Γ— 10⁹³(94-digit number)
53851979907089498627…16232390192303481919
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2+1 β†’
5
2^4 Γ— origin βˆ’ 1
1.077 Γ— 10⁹⁴(95-digit number)
10770395981417899725…32464780384606963839
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2+1 β†’
6
2^5 Γ— origin βˆ’ 1
2.154 Γ— 10⁹⁴(95-digit number)
21540791962835799451…64929560769213927679
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2+1 β†’
7
2^6 Γ— origin βˆ’ 1
4.308 Γ— 10⁹⁴(95-digit number)
43081583925671598902…29859121538427855359
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2+1 β†’
8
2^7 Γ— origin βˆ’ 1
8.616 Γ— 10⁹⁴(95-digit number)
86163167851343197804…59718243076855710719
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2+1 β†’
9
2^8 Γ— origin βˆ’ 1
1.723 Γ— 10⁹⁡(96-digit number)
17232633570268639560…19436486153711421439
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2+1 β†’
10
2^9 Γ— origin βˆ’ 1
3.446 Γ— 10⁹⁡(96-digit number)
34465267140537279121…38872972307422842879
Verify on FactorDB β†—Wolfram Alpha β†—

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 β€” the large number shown above β€” 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 β†’
β˜…β˜…β˜†β˜†β˜†
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 Γ— 3 Γ— 5 Γ— 7 Γ— …), the result is the first prime in the chain. The origin is deliberately divisible by this primorial β€” that divisibility is part of the proof.

Prime Chain Origin = First Prime Γ— Primorial (2Β·3Β·5Β·7Β·11·…)
Source: Primecoin prime.cpp β€” CheckPrimeProofOfWork()

This is why the origin has many small prime factors β€” those factors are the primorial divisor. The chain then extends from the first prime using the 1CC formula:

1CC: p₁ (first prime), pβ‚‚ = 2p₁ + 1, p₃ = 2pβ‚‚ + 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 223900

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 c3a217a0c24770ef86d90d0d792ef5bd4d2241c692791121acb9aada23d97bfc

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 β†’ Debug Window β†’ 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 #223,900 on Chainz β†—
Circulating Supply:57,862,771 XPMΒ·at block #6,827,332 Β· updates every 60s
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